Flapper on Frac Plug That Allows Pumping Down a New Plug

ABSTRACT

A zonal isolation device conveyed into the wellbore with a propped flapper valve. The zonal isolation device comprises a deformable sealing element and a support ring movably disposed within the inner bore of the sealing element. A flapper valve coupled to the support ring is configured to engage a sealing surface of support ring. The flapper valve blocks fluid flow through the zonal isolation device in a fully closed position, allows unrestricted fluid flow through the zonal isolation device in a fully open position, and allows restricted fluid flow through the zonal isolation device when held by a propping component in an intermediate or partially open position. The zonal isolation device is anchored to the wellbore by an anchoring assembly engaged with a wedge coupled to the downhole end of the sealing element.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of and claims priority to U.S. patentapplication Ser. No. 14/800,358 filed Feb. 25, 2020 and published asU.S. Patent Application Publication No. 2021/0054714 A1, which claimspriority to U.S. Provisional Patent Application No. 62/890,991, filed onAug. 23, 2019, both entitled “Flapper on Frac Plug That Allows PumpingDown a New Plug,” both of which are hereby incorporated by reference intheir entirety.

BACKGROUND

Wellbores are drilled into the earth for a variety of purposes includingaccessing hydrocarbon bearing formations. A variety of downhole toolsmay be used within a wellbore in connection with accessing andextracting such hydrocarbons. Throughout the process, it may becomenecessary to isolate sections of the wellbore in order to createpressure zones. Zonal isolation devices, such as frac plugs, bridgeplugs, packers, and other suitable tools, may be used to isolatewellbore sections.

Frac plugs and other zonal isolation devices are commonly run into thewellbore on a conveyance such as a wireline, work string or productiontubing. Such tools typically have either an internal or external settingtool, which is used to set the downhole tool within the wellbore andhold the tool in place. Upon reaching a desired location within thewellbore, the downhole tool is actuated by hydraulic, mechanical,electrical, or electromechanical means to seal off the flow of liquidaround the downhole tool. After a treatment operation, zonal isolationdevices may be removed from the wellbore by various methods, includingdissolution and/or drilling. Certain zonal isolation devices may havenumerous constituent parts, complicating removal. Some zonal isolationdevices may include a ratchet or similar mechanism to retain the devicein a set configuration. Ratchets may allow shifting or “free play”within each ratchet increment.

BRIEF DESCRIPTION OF THE DRAWINGS

These drawings illustrate certain aspects of some of the embodiments ofthe present disclosure, and should not be used to limit or define theclaims.

FIG. 1 is a diagram illustrating an environment for a zonal isolationdevice according to certain embodiments of the present disclosure.

FIG. 2 is a diagram illustrating an environment for a set zonalisolation device according to certain embodiments of the presentdisclosure.

FIG. 3 is a side view of a zonal isolation device according to certainembodiments of the present disclosure.

FIG. 4 is cross-sectional view of a zonal isolation device according tocertain embodiments of the present disclosure.

FIG. 5 is cross-sectional view of a zonal isolation device with anexpanded sealing element according to certain embodiments of the presentdisclosure.

FIG. 6 is a side view of a zonal isolation device with linked slipsegments according to certain embodiments of the present disclosure.

FIG. 7 is a cross-sectional view of a set zonal isolation device and aseated ball in a wellbore environment according to certain embodimentsof the present disclosure.

FIG. 8 is a perspective view of an unset zonal isolation deviceaccording to certain embodiments of the present disclosure.

FIG. 9 is a cross-sectional view of a zonal isolation device engagedwith a setting tool according to certain embodiments of the presentdisclosure.

FIG. 10 is a cross-sectional view of a zonal isolation device having afloating expansion ring engaged with a setting tool according to certainembodiments of the present disclosure.

FIG. 11 is a cross-sectional view of a zonal isolation device having apump-down ring engaged with a setting tool according to certainembodiments of the present disclosure.

FIG. 12 is a cross-sectional view of a zonal isolation device engagedwith a setting tool having an upper and lower mandrel according tocertain embodiments of the present disclosure.

FIG. 13 is a cross-sectional view of a set zonal isolation deviceincluding a lower mandrel according to certain embodiments of thepresent disclosure.

FIG. 14 is a perspective view of a zonal isolation device including anexpandable collar according to certain embodiments of the presentdisclosure.

FIG. 15 is a cross-sectional view of a zonal isolation device includingan expandable collar according to certain embodiments of the presentdisclosure.

FIG. 16 is a diagram illustrating an environment for a zonal isolationdevice according to certain embodiments of the present disclosure.

FIG. 17 is a cross-sectional view of a zonal isolation device with arotatable sealing component according to certain embodiments of thepresent disclosure.

FIG. 18A is a cross-sectional view of a zonal isolation device with arotatable sealing component in an open position according to certainembodiments of the present disclosure.

FIG. 18B is a cross-sectional view of a zonal isolation device with arotatable sealing component in a closed position according to certainembodiments of the present disclosure.

FIG. 19 is a cross-sectional view of a zonal isolation device with arotatable sealing component according to certain embodiments of thepresent disclosure.

FIG. 20A is a top view of zonal isolation device of FIG. 19 with arotatable sealing component in an open position according to certainembodiments of the present disclosure.

FIG. 20B is a top view of a zonal isolation device of FIG. 19 with arotatable sealing component in a closed position according to certainembodiments of the present disclosure.

FIG. 21 is a cross-sectional view of a zonal isolation device with arotatable sealing component and having a floating support ring engagedwith a setting tool according to certain embodiments of the presentdisclosure.

FIG. 22 is a cross-sectional view of a zonal isolation device with arotatable sealing component after setting.

FIG. 23 is a cross-sectional view of a zonal isolation device with aflapper with a rupture disc according to certain embodiments of thepresent disclosure.

FIG. 24 is a cross-sectional view of a zonal isolation device with aflapper with a releasable hinge according to certain embodiments of thepresent disclosure.

FIG. 25 is a cross-sectional view of a zonal isolation device with apropped flapper with a spring as the propping component according tocertain embodiments of the present disclosure.

FIG. 26 is a cross-sectional view of a zonal isolation device with apropped flapper with a spring as the propping component according tocertain embodiments of the present disclosure.

FIG. 27 is a cross-sectional view of a zonal isolation device with apropped flapper with a strut as the propping component according tocertain embodiments of the present disclosure.

While embodiments of this disclosure have been depicted, suchembodiments do not imply a limitation on the disclosure, and no suchlimitation should be inferred. The subject matter disclosed is capableof considerable modification, alteration, and equivalents in form andfunction, as will occur to those skilled in the pertinent art and havingthe benefit of this disclosure. The depicted and described embodimentsof this disclosure are examples only, and not exhaustive of the scope ofthe disclosure.

DESCRIPTION OF CERTAIN EMBODIMENTS

Illustrative embodiments of the present disclosure are described indetail herein. In the interest of clarity, not all features of an actualimplementation may be described in this specification. It will of coursebe appreciated that in the development of any such actual embodiment,numerous implementation-specific decisions may be made to achieve thespecific implementation goals, which may vary from one implementation toanother. Moreover, it will be appreciated that such a development effortmight be complex and time-consuming, but would nevertheless be a routineundertaking for those of ordinary skill in the art having the benefit ofthe present disclosure.

As used herein, the terms “casing,” “casing string,” “casing joint,” andsimilar terms refer to a substantially tubular protective lining for awellbore. Casing can be made of any material, and can include tubularsknown to those skilled in the art as casing, liner, and tubing. Incertain embodiments, casing may be constructed out of steel. Casing canbe expanded downhole, interconnected downhole and/or formed downhole insome cases.

As used herein, the term “downhole surface” and similar terms refer toany surface in the wellbore or subterranean formation. For example,downhole surfaces may include, but are not limited to a wellbore wall,an inner tubing string wall such as a casing wall, a wall of anopen-hole wellbore, and the like.

As used herein, the term “degradable” and all of its grammaticalvariants (e.g., “degrade,” “degradation,” “degrading,” “dissolve,”dissolving,” and the like), refers to the dissolution or chemicalconversion of solid materials such that reduced-mass solid end productsare formed by at least one of solubilization, hydrolytic degradation,biologically formed entities (e.g., bacteria or enzymes), chemicalreactions (including electrochemical and galvanic reactions), thermalreactions, reactions induced by radiation, or combinations thereof. Incomplete degradation, no solid end products result. In some instances,the degradation of the material may be sufficient for the mechanicalproperties of the material to be reduced to a point that the material nolonger maintains its integrity and, in essence, falls apart or sloughsoff into its surroundings. The conditions for degradation are generallywellbore conditions where an external stimulus may be used to initiateor effect the rate of degradation, where the external stimulus isnaturally occurring in the wellbore (e.g., pressure, temperature) orintroduced into the wellbore (e.g., fluids, chemicals). For example, thepH of the fluid that interacts with the material may be changed byintroduction of an acid or a base. The term “wellbore environment”includes both naturally occurring wellbore environments and materials orfluids introduced into the wellbore.

Directional terms, such as “up”, “below”, “downhole”, etc. are used inthe present disclosure. In general, use of the terms “up”, “above”,“upper”, “uphole”, “top”, or other like terms refer to a directiontoward the surface of the earth along a wellbore; likewise, “down”,“lower”, “below”, “downhole”, or other like terms refer to a directionaway from the surface of the earth along the wellbore, regardless of thewellbore orientation. For example, in a horizontal wellbore, twolocations may be at the same level (i.e., depth within a subterraneanformation), the location closer to the well surface (by comparing thelengths along the wellbore from the wellbore surface to the locations)is referred to as “above” the other location.

As used herein, the term “coupled” and its grammatical variants refer totwo or more components, pieces, or portions that may be used operativelytogether, that are joined together, that are linked together. Forexample, coupled components may include, but are not limited tocomponents that are detachably coupled, shearably coupled, coupled bycompression fit, coupled by interference fit, joined, linked, connected,coupled by a bonding agent. or the like.

The present disclosure relates to downhole tools used in the oil and gasindustry. Particularly, the present disclosure relates to an apparatusfor isolating zones in a wellbore and methods of use.

More specifically, the present disclosure relates to a zonal isolationdevice, comprising: a tubular body having a fluid communication pathwayformed along a longitudinal axis comprising: a sealing elementcomprising a deformable material and an inner bore forming at least aportion of the fluid communication pathway; an expansion ring disposedwithin the bore of the sealing element; a wedge engaged with a downholeend of the sealing element; and an anchoring assembly engaged with thewedge. In certain embodiments, the tubular body further comprises an endelement adjacent the anchoring assembly.

In some embodiments, the present disclosure relates to a methodcomprising: inserting into a wellbore a zonal isolation device disposedon a setting tool adapter kit comprising a mandrel, wherein the zonalisolation device comprises: a sealing element comprising a deformablematerial and an inner bore; an expansion ring movably disposed withinthe inner bore of the sealing element; a wedge engaged with a downholeend of the sealing element; an anchoring assembly engaged with thewedge; and an end element adjacent the anchoring assembly and detachablycoupled to the mandrel; and actuating to pull upwardly on the mandrel,wherein the upward movement of the mandrel longitudinally compresses thezonal isolation device, causing the expansion ring to axially moverelative to the sealing element and radially expand the sealing elementinto a sealing engagement with a downhole surface.

In some embodiments, the present disclosure relates to a zonal isolationsystem, comprising: a setting tool adapter kit comprising a mandrel; asealing element disposed on the mandrel for sealing engagement with adownhole surface; an expansion ring movably disposed on the mandrel andengaged with the sealing element; a wedge disposed on the mandrel; andan anchoring assembly disposed around the mandrel for locking engagementwith a downhole surface.

Among the many potential advantages of the apparatus and methods of thepresent disclosure, only some of which are alluded to herein, the zonalisolation device of the present disclosure may be provided with fewercomponent parts. Further, a zonal isolation device according to certainembodiments of the present disclosure may include a large inner diameterthan other devices, which may prove advantageous for increasing flowrates during production operations. Further, a zonal isolation deviceaccording to certain embodiments of the present disclosure may beprovided with more controlled dissolution characteristics due to, forexample, fewer components parts. In some embodiments, the zonalisolation device of the present disclosure may retain a setconfiguration without a ratchet or similar mechanism, which may resultin a lower cost tool with better dissolution characteristics and/or mayeliminate the shifting that may occur in devices with a ratchet. In someembodiments, the zonal isolation device of the present disclosure mayprovide a more stable set frac plug, as the sealing element may provideadditional stability.

The zonal isolation device is generally depicted and described herein asa hydraulic fracturing plug or “frac” plug. It will be appreciated bythose skilled in the art, however, that the principles of thisdisclosure may equally apply to any of the other aforementioned types ofcasing or borehole isolation devices, without departing from the scopeof the disclosure. Indeed, the zonal isolation device may be any of afrac plug, a wellbore packer, a deployable baffle, a bridge plug, or anycombination thereof in keeping with the principles of the presentdisclosure.

Embodiments of the present disclosure and their advantages are bestunderstood by references to FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, and 15, where like numbers are used to indicate like andcorresponding features.

Representatively illustrated in FIG. 1 is a zonal isolation deviceemployed in a wellbore system 300 according to certain embodiments ofthe present disclosure. A wellbore system 300 for sealing a zonalisolation device in a wellbore includes a service rig 110 extending overand around a wellbore 120. The service rig 110 may comprise a drillingrig, a completion rig, a workover rig, or the like. In some embodiments,the service rig 110 may be omitted and replaced with a standard surfacewellhead completion or installation, without departing from the scope ofthe disclosure. The wellbore 120 is within a subterranean formation 150and has a casing 130 lining the wellbore 120, the casing 130 held intoplace by cement 122. In some embodiments, the wellbore casing 130 may beomitted from all or a portion of the wellbore 120 and the principles ofthe present disclosure may alternatively apply to an “open-hole”environment. Although shown as vertical, the wellbore 120 may includehorizontal, vertical, slant, curved, and other types of wellbore 120geometries and orientations. As depicted, the zonal isolation device 200may include a tubular body 205 comprising a sealing element 100, a wedge180, an anchoring assembly 215, and an end element 170. The zonalisolation device 200 may be coupled to a setting tool adapter kit 160for conveyance into the wellbore and setting. The setting tool adapterkit 160 may comprise a mandrel that may engage with the zonal isolationdevice 200. The zonal isolation device 200 and the setting tool adapterkit 160 may be moved down the wellbore 120 via a conveyance 140 thatextends from the service rig 110 to a target location. The conveyance140 can be, for example, tubing-conveyed, wireline, slickline, workstring, or any other suitable means for conveying zonal isolationdevices into a wellbore. In certain embodiments, the conveyance 140 maycomprise a setting tool and be coupled to setting tool adapter kit 160.As an alternative, in some embodiments, a conveyance 140 is not used andthe entire zonal isolation device 200 is pumped to location as anuntethered device. As depicted in FIG. 1, the setting tool is aninternal setting tool, but a person of skill would understand that anexternal setting tool could be used in one or more embodiments of thepresent disclosure. Examples of suitable setting tools for certainembodiments of the present disclosure include, but are not limited toBaker 10, Baker 20, 3½ HES GO, and the like, or any other suitablesetting tool. In some embodiments, the zonal isolation device 200 may bepumped to the target location using hydraulic pressure applied from theservice rig 110. In such embodiments, the conveyance 140 serves tomaintain control of the zonal isolation device 200 as it traverses thewellbore 120 and provides the necessary power to actuate and set thezonal isolation device 200 upon reaching the target location. In otherembodiments, the zonal isolation device 200 freely falls to the targetlocation under the force of gravity. Upon reaching the target location,the zonal isolation device 200 may be actuated or “set” and therebyprovide a point of fluid isolation within the wellbore 120. Setting mayoccur by longitudinal compression of the tubular body 205, which maymove the sealing element 100 into sealing engagement with one or moredownhole surfaces, and may also move the anchoring assembly 215 intolocking engagement with one or more downhole surfaces. After setting,the setting tool adapter kit 160 may disengage from the zonal isolationdevice 200 and be withdrawn from the wellbore 120.

The zonal isolation device 200 of FIG. 1 is depicted in an unsetconfiguration. In the unset configuration, the anchoring assembly 215 isconfigured such that the zonal isolation device can be moved uphole ordownhole without catching on the casing 130 of the wellbore 120. Oncethe zonal isolation device 200 reaches the desired location, the settingtool adapter kit 160 may be actuated (e.g, by the setting tool) to setthe zonal isolation device 200, anchoring it into place and moving itinto a sealing engagement. It should be noted that while FIG. 1generally depicts a land-based operation, those skilled in the art wouldreadily recognize that the principles described herein are equallyapplicable to operations that employ floating or sea-based platforms andrigs, without departing from the scope of the disclosure. It should alsobe noted that a plurality of zonal isolation devices 200 may be placedin the wellbore 120. In some embodiments, for example, two or more zonalisolation devices 200 may be arranged in the wellbore 120 to divide thewellbore 120 into smaller intervals or “zones” for a particularoperation (e.g., hydraulic stimulation).

FIG. 2 depicts a zonal isolation device 200 in a set and anchoredconfiguration disposed within a wellbore 120. In the anchoredconfiguration, the anchoring assembly 215 is radially expanded outwardsand engages and grips the casing 130 lining the wellbore 120. In the setconfiguration, the sealing element 100 is radially expanded outwardsinto sealing engagement with the casing 130 or other downhole surface.Sealing engagement of the sealing element 100 may effectively preventfluid flow around the zonal isolation device 200. Although fluid maystill flow through the internal bore of the zonal isolation device 200,a sealing device may be used to seal the internal flow of the zonalisolation device 200, as discussed further below. In such a manner, thezonal isolation device 200 may seal the wellbore 120 at a targetlocation, preventing fluid flow past the zonal isolation device 200.

In some embodiments, the anchoring assembly 215 and sealing element 100are sufficient to hold the zonal isolation device 200 in a setconfiguration, when in locking engagement and sealing engagement with adownhole surface, respectively. In certain embodiments, the zonalisolation device 200 may retain a set configuration without a ratchet orsimilar component.

FIGS. 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 depict a zonalisolation device 200 according to certain embodiments of the presentdisclosure. The zonal isolation device 200 may include a tubular body205 comprising a sealing element 100, wedge 180, anchoring assembly 215,end element 170, and expansion ring 190. The zonal isolation device 200may include a fluid communication pathway 206 formed along alongitudinal axis. In some embodiments, one or more components of thezonal isolation device 200 may form at least a portion of the fluidcommunication pathway 206.

The sealing element 100 may comprise an inner bore 105 that forms atleast a part of the fluid communication pathway 206. In certainembodiments, a wedge 180 may be adjacent to the downhole end 101 of thesealing element 100. The wedge 180 and the sealing element 100 may becoupled or uncoupled. In some embodiments, wedge 180 and sealing element100 may engage each other with interlocking tapered surfaces at aninterface 102. In certain embodiments, wedge 180 and sealing element 100may be coupled together by a compression fit or an interference fit. Forexample, wedge 180 and sealing element 100 may be longitudinallycompressed together after the zonal isolation device 200 is set.

The sealing element 100 may be elastically or plastically deformable,and may be composed of any suitable elastically or plasticallydeformable material including, but not limited to, elastomers (includingbut not limited to rubber), polymers (including but limited toplastics), or metal. One of ordinary skill in the art will understandthat the material selected and the deformable nature (elastic orplastic) is an understood design choice generally dictated by theapplication of the system and method described herein. Furthermore, oneof ordinary skill in the art will understand that the material may befurther selected to ease the removal of zonal isolation device 200 by,for example, choosing a material that easily broken up if drilled out ora material that is dissolvable.

With reference to FIG. 4, the zonal isolation device may comprise anexpansion ring 190. The expansion ring 190 may be disposed within thesealing element 100. In some embodiments, the expansion ring 190 may bemovably disposed within an inner bore 105 of the sealing element 100. Inan unset configuration of the zonal isolation device 200, the expansionring 190 may be disposed adjacent to the sealing element 100, within theinner bore 105 of the sealing element 100, or partially disposed insidethe sealing element 100. As shown in FIG. 5, the expansion ring 190 maycause the sealing element 100 to radially expand by moving towards thedownhole end 101 of the sealing element 100. In certain embodiments, theexpansion ring 190 may cause the sealing element 100 to radially expandinto sealing engagement with a downhole surface. For example, settingthe zonal isolation device 200 may cause the expansion ring 190 toaxially move towards a downhole end 101 of the sealing element 100. Theexpansion ring 190 may be shaped such that engaging with a tapered innersurface of the inner bore 105 of the sealing element 100 radiallyexpands the sealing element 100. The expansion ring 190 may comprisecuts or teeth 191 angled in an upwards orientation. The teeth 191 mayengage with the inner bore 105 of the sealing element 100 and preventupward movement of the expansion ring 190 relative to the sealingelement 100. In some embodiments, the teeth 191 may allow the expansionring 190 to maintain a position within the sealing element 100 inresponse to forces acting to remove it from the sealing element 100.Such forces may include, for example, a force caused during ejection ofa ball or flow forces acting on the expansion ring 190 during flowbackof fluids. In other applications, the sealing element 100 is attached tothe wedge 180 (e.g., at interface 101/102) so that the expansion ring190 causes the sealing element 100 to stretch into a frustum shape. Theinterface 101/102 is affixed to each other, and the expansion ring 190stretches the top of the sealing element 100 (e.g., rubber) while thebottom of the sealing element 100 (e.g., rubber) is bonded to the wedge180.

In some embodiments, the expansion ring 190 may also act be configuredto receive a sealing device (e.g., a frac ball, frac dart, or the like).As shown in FIG. 7, a sealing ball or “frac ball” 300 may be dropped andland on the expansion ring 190. As depicted, the sealing element 100 isin sealing engagement with the wellbore casing 130 and the slip segments216 are in locking engagement with the casing 130. When the sealing ball302 is seated on the expansion ring 190 and the zonal isolation device200 is set, fluid flow past or through the zonal isolation device 200 inthe downhole direction is effectively prevented. For example, thesealing ball 302 may seal off the fluid communication pathway 206 formedalong a longitudinal axis of the zonal isolation device 200. At thatpoint, wellbore operations such as completion or stimulation operationsmay be undertaken by injecting a treatment or completion fluid into thewellbore 120 and forcing the treatment/completion fluid out of thewellbore 120 and into a subterranean formation above the wellboreisolation device 200. For example, after the sealing ball 302 is seated,fluid may be introduced into the wellbore 120 at a pressure sufficientto create or enhance one or more fractures within the subterraneanformation. In some embodiments, a different sealing device such as afrac dart may be used in place of the sealing ball 302.

The wedge 180 may have a frustoconical shape and be disposed between thesealing element 100 and the anchoring assembly 215. In certainembodiments, the anchoring assembly 215 is engaged with the wedge 180.In some embodiments, the wedge may be engaged with a downhole end 101 ofthe sealing element 100. In some embodiments, the wedge 180 may comprisea single frustoconical surface 182 (e.g., as depicted in FIG. 8). Inother embodiments, the wedge 180 may include a plurality of planartapered outer surfaces 181. In some embodiments, the planar taperedouter surfaces 181 may be finned and comprise fins 183 (e.g., asdepicted in FIG. 3). The planar tapered outer surfaces 181 maycorrespond to at least a portion of the anchoring assembly 215. Forexample, each planar tapered outer surface 181 may correspond to andslidably engage with the inner surfaces 217 of a plurality of slipsegments 216 of the anchoring assembly 215. In some embodiments, theplanar tapered outer surfaces 181 and inner surfaces 217 of theanchoring assembly 215 may be complimentary, tapered, angled, orotherwise configured to engage one another upon setting of the zonalisolation device 200 in a wellbore (e.g., the wellbore 120 of FIG. 1).The planar tapered outer surface 181 and slip segments 216 may be shapedsuch that, upon sufficient movement of the wedge 180 relative to theslip segments 216, the slip segments 216 will be forced up the planartapered outer surfaces 181 and radially expanded away from the wedge 180towards a downhole surface.

In certain embodiments, the anchoring assembly 215 allows the zonalisolation device to hold its position within the wellbore. As depictedin FIG. 3, the anchoring assembly 215 may comprise a plurality of slipsegments 216. Although depicted as arcuate-shaped slip segments 216, theslip segments 216 may be any suitable shape. The slip segments 216 maybe deformed radially from the longitudinal axis of the zonal isolationdevice 200, thereby engaging a downhole surface such as a casing 130.The anchoring assembly 215 may be engaged by movement of the end element170 upward, forcing a portion of the anchoring assembly 215 onto aportion of the wedge 180 and expanding the slip segments 216 outwardlytoward the downhole surface. Expanding the slip segments 216 outwardlymay move the anchoring assembly 215 into locking engagement with thedownhole surface. The locking engagement of the anchoring assembly 215may hold the zonal isolation device 200 in position after setting,preventing upward or downward movement in the wellbore 120.

The plurality of slip segments 216 may be fully interconnected (e.g., asdepicted in FIGS. 6 and 8), partially interconnected (e.g., as depictedin FIG. 3), or not connected. In some embodiments, at least two of theplurality of slip segments 216 may be interconnected by a shearable link219 that may shear upon axial expansion of the slip segments 216. Incertain embodiments, the sharable links 219 may be configured such that,upon sufficient movement of the wedge 180 relative to the slip segments216, one or more fins 183 may shear one or more shearable links 219.

The slip segments 216 may comprise slip inserts 218 embedded therein.Slip inserts 218 may be wear buttons, wickers, wedges, or any otherelement for reducing wear of the slip segments 216. Slip inserts 218 mayprotrude from the slip segments 216 to penetrate or bite a downholesurface. Although each slip segment 216 is shown having four slipinserts 218 respectfully, it will be appreciated that any number of slipinserts, including one or a plurality (three, four, five, ten, twenty,and the like) of slip inserts may be embedded in each slip, withoutdeparting from the scope of the present disclosure. The slip segments216 may have the same or a different number of slip inserts 218, withoutdeparting from the scope of the present disclosure. The slip inserts 218in FIGS. 3, 6, and 8 are depicted as cylindrical. However, the slipinserts 218 may be squared shaped, frustum shaped, conical shaped,spheroid shaped, pyramid shaped, polyhedron shaped, octahedron shaped,cube shaped, prism shaped, hemispheroid shaped, cone shaped, tetrahedronshaped, cuboid shaped, and the like, and any combination thereof,without departing from the scope of the present disclosure. The slipinserts 218 may be partially one shape and partially one or more othershapes. In some embodiments, the slip inserts 218 may be hardened orcoated to penetrate a downhole surface. For example, the slip inserts218 may comprise a surface treatment including, but not limited to roughsurfaces and edges, hardened coatings (both metallurgical andnon-metallurgical bonded), ratchet teeth, etc.

In some embodiments, the slip inserts 218 may include hardened metals,ceramics, and any combination thereof. The material forming the slipinserts 218 may be an oxide or a non-oxide material. In certainembodiments, the thickness of a material may be increased in order toachieve the desired compressive strength. For example, in someembodiments the material forming the slip insert 218 may include, but isnot limited to, iron (e.g., cast iron), steel, titanium, zircon, acarbide (e.g., tungsten carbide, a tungsten carbide alloy (e.g., alloyedwith cobalt), silicon carbide, titanium carbide, boron carbide, tantalumcarbide), a boride (e.g., osmium diboride, rhenium boride, tungstenboride, zirconium boride, iron tetraboride), a nitride (e.g., siliconnitride, titanium nitride, boron nitride, cubic boron nitride, boroncarbon nitride, beta carbon nitride), diamond, synthetic diamond, silica(e.g., amorphous silica), an oxide (e.g., aluminum oxide, fused aluminumoxide, zirconium oxide, beryllium oxide, alumina-chrome oxide),corundite, topaz, synthetic topaz, garnet, synthetic garnet,lonsdaleite, and any combination thereof.

An end element 170 may be positioned at or secured at the downhole endof the zonal isolation device 200. As will be appreciated, the endelement 170 of the wellbore isolation device 200 could be a mule shoe,or any other type of section that serves to terminate the structure ofthe wellbore isolation device 200, or otherwise serves as a connectorfor connecting the wellbore isolation device 200 to other tools, such asa valve, tubing, or other downhole equipment. The end element 170 maycomprise end element inserts 171 embedded therein. End element inserts171 may be wear buttons, wickers, wedges, or any other element forreducing wear of the end element 170. End element inserts 171 may be anyshape or material discussed above with respect to slip inserts 218. Incertain embodiments, the end element 170 may be adjacent, engaged with,and/or coupled to the anchoring assembly 215. For example, as shown inFIG. 8, the end element 170 may be coupled to the anchoring assembly 215by a dovetail coupling 173. In some embodiments, as shown in FIG. 8, theend element 170 may include flow back channels 172 that allow flow backof fluids (e.g., production fluids).

With reference to FIG. 9, a setting tool adapter kit 160 may be coupledto the zonal isolation device 200. In some embodiments, the setting tooladapter kit 160 comprises a mandrel 161 that may engage with the zonalisolation device 200. In some embodiments, the setting tool adapter kit160 comprises a setting sleeve 167 disposed around the mandrel 161. Incertain embodiments, the mandrel 161 may be slidably engaged with thesetting sleeve 167. In some embodiments, the mandrel 161 may be able tomove relative to the setting sleeve 167. The setting tool adapter kit160 may include parts that allow a conventional setting tool to be usedwith zonal isolation device 200. In certain embodiments, the mandrel 161may be disposed within the zonal isolation device 200 along alongitudinal axis. In some embodiments, the mandrel 161 may be disposedin a fluid communication pathway 206 of the zonal isolation device 200.As depicted in FIG. 9, the mandrel 161 may be coupled to the end element170. In some embodiments, the mandrel 161 may be detachably or shearablycoupled to the end element 170. In certain embodiments, the mandrel 161may be coupled to the end element 170 by shearable threads. As discussedabove, the setting tool adapter kit 160 including mandrel 161 may beactuated upward to longitudinally compress the zonal isolation device200. The setting tool or setting tool adapter kit 160 may operate viavarious mechanisms including, but not limited to, hydraulic setting,mechanical setting, setting by swelling, setting by inflation, and thelike.

As depicted in FIGS. 9, 10, 11, 12, and 13, the components of the zonalisolation device 200 may be disposed on the mandrel 161. For example,the anchoring assembly 215, the wedge 180, the sealing element 100, andthe expansion ring 190 may be disposed on or around the mandrel 161. Insome embodiments, one or more of the anchoring assembly 215, the wedge180, the sealing element 100, and the expansion ring 190 may be coupled(e.g., shearably coupled) to the mandrel 161. The expansion ring 190 maybe coupled to the sealing element 100, as shown in FIG. 9, or uncoupledfrom the sealing element 100 or “floating,” as shown in FIG. 10. Incertain embodiments, the mandrel 161 may be coupled (e.g., by threads)to one or more components of the zonal isolation device 200 with a givenlevel of tightness. In certain embodiments, the tightness of a couplingbetween the mandrel 161 and one or more components of the zonalisolation device 200 may be from about 0.5 ft·lb to about 50 ft·lb.

In some embodiments, one or more components of the setting tool adapterkit 160 or a setting tool coupled to the setting tool adapter kit 160may be actuated to force the end element 170 upward by drawing themandrel 161 upward. Drawing the end element 170 upward may force theanchoring assembly 215 upward such that the slip segments 216 engagewith the wedge 180. For example, drawing the end element 170 upward mayforce the slip segments 216 up a surface of the wedge 180, causing theslip segments 216 to radially expand into locking engagement with adownhole surface.

In some embodiments, one or more portions of the setting tool adapterkit 160 may hold the expansion ring 190 stationary relative to thesealing element 100 and/or other elements of the zonal isolation device200. In certain embodiments, the setting sleeve 167 may restrict upwardmovement of the expansion ring 190 during upward movement of the mandrel161. For example, the setting tool 160 may comprise one or moreretention elements shaped to restrict the upward movement of theexpansion ring 190 during upward movement of the mandrel 161 and othercomponents of the zonal isolation device 200. In certain embodiments,the retention element may include a ridge, flange, tab, pin, sleeve, orother element suitable to restrict upward movement of the expansion ring190 during upward movement of the mandrel 161. Actuating the settingtool 160 may cause the sealing element 100 to move upward relative tothe expansion ring 190, forcing the expansion ring 190 towards thedownhole end 101 of the sealing element 100. Shifting of the expansionring 190 towards the downhole end 101 of the sealing element 100 mayradially expand the sealing element 100 into sealing engagement with adownhole surface. For example, a tapered surface of the expansion ring190 may engage with a tapered surface of the inner bore 105 of thesealing element 100.

In certain embodiments, the zonal isolation device 200 may be made up inthe form depicted in FIG. 9, where the expansion ring 190 is disposedwithin the sealing element 100 but the sealing element 100 is notsignificantly expanded. In some embodiments, the zonal isolation device200 may be run in the wellbore 120 in this configuration. As depicted inFIG. 11, the zonal isolation device 200 may be run in the wellbore 120in a configuration where the expansion ring 190 is disposed within thesealing element 100 such that at least a portion of the sealing element100 is at least partially expanded. In some embodiments, a partiallyexpanded sealing element 100 may improve pump down efficiency.

In certain embodiments, the mandrel 161 may be shearably coupled to oneor more components of the zonal isolation device 200 by one or moreshear devices, including, but not limited to shear threads, shear pins,a shear ring, shear screws, shearable ridges, and the like, or any othershearable device. In embodiments where the mandrel 161 is shearablycoupled to one or more components of the zonal isolation device 200, themandrel 161 may overcome a shear force provided by the shear device. Forexample, during or after setting, enough upward force may be applied tothe mandrel 161 to shear one or more shear devices and decouple themandrel from one or more components of the zonal isolation device 200.In some embodiments, the mandrel 161 may be shearably coupled to the endelement 170 by a shear device. In some embodiments, the shear forcenecessary to overcome one or more shear devices of the zonal isolationdevice 200 is from about 10,000 lb_(f) to 50,000 lb_(f).

As discussed above, the end element 170 may be coupled or uncoupled tothe anchoring assembly 215. As depicted in FIG. 7, in embodiments wherethe end element 170 is not coupled to the anchoring assembly 215, theend element 170 may fall downhole and away from the zonal isolationdevice 200 after the mandrel 161 is actuated and decouples from the endelement 170. In other embodiments where the end element 170 is coupledto the anchoring assembly 215, the end element 170 may be retained aspart of the zonal isolation device after the setting tool 160 andmandrel 161 are removed. After setting the zonal isolation device 200,the setting tool 160 and mandrel 161 may be removed from the zonalisolation device 200 and the wellbore 120.

In some embodiments, the zonal isolation device 200 may be run into awellbore 120 via conveyance 140 in a sealed configuration. For example,as depicted in FIG. 13, the zonal isolation device may be run into thewellbore 120 with a lower mandrel 163 in the fluid communication pathway206 of the zonal isolation device 200. The lower mandrel 163 may bedisposed within the zonal isolation device 200 along a longitudinalaxis. In certain embodiments, the lower mandrel 163 may be coupled to atleast one of the end element 170, the anchoring assembly 215, the wedge180 or the sealing element 100. The lower mandrel 163 may seal off thefluid communication pathway 206 formed along a longitudinal axis of thezonal isolation device 200, allowing completion or stimulationoperations to take place without the use of a frac ball or otheradditional sealing device. The lower mandrel 163 may be coupled to asetting tool 160 while the zonal isolation device 200 is run into thewellbore 120. After setting, the setting tool, another mandrel (notshown), or the adapter kit 160 may be decoupled from the lower mandrel163, leaving the lower mandrel 163 in place such that the zonalisolation device 200 is in a sealed configuration.

FIG. 13 depicts a zonal isolation device 200 in a set configuration.Before setting, the lower mandrel 163 may extend from the end element170 to the anchoring assembly 215. During setting of the zonal isolationdevice 200, the lower mandrel 163 may move upwards into the wedge 180before decoupling from the setting tool adapter kit 160 or othercomponent. In some embodiments, the lower mandrel 163 may include asealing surface 162 that seals the fluid communication pathway 206 ofthe zonal isolation device 200. The sealing surface 162 may include alarger diameter than at least one other portion of the lower mandrel 163and may effectively prevent fluid flow around the lower mandrel 163. Thelower mandrel 163 may comprise a dissolvable or degradable material. Insome embodiments, as depicted in FIGS. 12 and 13, the lower mandrel 163may comprise a set screw 168 that may couple the lower mandrel 163 tothe end element 170. In some embodiments, the set screw 168 retains thelower mandrel 163 in the end element 170 and prevents it from decouplingfrom the end element 170.

As shown in FIG. 12, a lower mandrel 163 may be coupled to a settingtool 160 including an upper mandrel 164. The lower mandrel 163 may bedetachably or shearably coupled to the upper mandrel 164, for example,by one or more shearable devices. Also depicted in FIG. 12 is a settingtool 160 comprising a protective sleeve 165. The protective sleeve 165may include a flange or extended rim of the setting tool 160. Theprotective sleeve 165 may engage with an uphole end of a sealing element100. For example, as depicted in FIG. 12, the sealing element 100 mayengage an inner surface 166 of the protective sleeve 165. In certainembodiments, at least a portion of the sealing element 100 may have adiameter smaller than the diameter of the inner surface 166 of theprotective sleeve 165. This configuration may improve pumping efficiencyas the zonal isolation device 200 is pumped or run into the wellbore120. In certain embodiments, this configuration may reduce the chance ofa “preset,” where the zonal isolation device 200 sets prior to reachingthe target location.

For example, in certain embodiments, one or more components of the zonalisolation device 200 may include a pump-down ring. A pump-down ring may,in certain embodiments, be a portion of a component of the zonalisolation device 200 or the setting tool adapter kit 160 with anincreased outer diameter relative to at least one other portion of thecomponent. For example, as depicted in FIG. 11, the sealing element 100may include a pump-down ring portion 103 having an increased outerdiameter relative to the rest of the sealing element 100. In certainembodiments, pump-down rings may increase pump down efficiency for thezonal isolation device 200.

With reference to FIGS. 14 and 15 the anchoring assembly 215 may includea one-piece expandable collar 220 with one or more scarf cuts 233 thatallow the expandable collar 220 to radially expand as it moves withrespect to the wedge 180, the end element 170, or both. In suchembodiments the expandable collar 220 may include a generally annularbody 230, an upper tapered surface 231 and a lower tapered surface 232.The upper tapered surface 231 may be configured to engage with andreceive the wedge 180, depicted with a single frustoconical surface 182.The lower tapered surface 232 may, in certain embodiments, be configuredto engage with and receive the end element 170. One or more scarf cuts233 may be defined in the body 230 and extend at least partially betweena first end 234 and a second end 235 of the expandable collar 220. Ascarf cut 233 is generally a spiral or helically extending cut slot inthe body 230. In certain embodiments, a scarf cut 233 may extend atleast partially around the body 230 or around the circumference of body230 more than once. A scarf cut 233 may be created by a variety ofmethods, including electrical discharge machining (EDM), sawing,milling, turning, or by any other machining techniques that result inthe formation of a slit through the annular body 230. Although depictedin FIGS. 14 and 15 as having one scarf cut 233, the zonal isolationdevice may comprise two or more scarf cuts 233.

One or more scarf cuts 233 may extend between the first end 234 andsecond end 235 at an angle 236 relative to one of the first end 234 andthe second end 235 or any other suitable plane extending normal to alongitudinal axis of the expandable collar 220. In the illustratedembodiment in FIGS. 14 and 15, the angle 236 of the one or more scarfcuts 233 is defined in the annular body 230 relative to the first end234. In some embodiments, the angle 236 of the one or more scarf cuts233 may be about 10°, about 15°, about 20°, about 40°, about 45°, orabout 50°. In some embodiments, the angle 236 of the one or more scarfcuts 233 may range from about 0° to about 45°. In some embodiments, theangle 236 of the one or more scarf cuts 233 may range from about 5° toabout 30°. As the angle 236 of the one or more scarf cuts 233 decreases,a circumferential length of the one or more scarf cuts 233correspondingly increases. A greater circumferential length of the oneor more scarf cuts 233 may, in certain embodiments, provide a largerexpansion potential of the expandable collar 220 without the expandablecollar 220 completely separating when viewed from an axial perspective.

The one or more scarf cuts 233 may permit diametrical expansion of theexpandable collar 220 to an expanded state and into locking engagementwith a downhole surface. In certain embodiments, due to the constructionof the expandable collar 220, a large flow area can be provided throughan inner diameter 237 of the body 230. During expansion of theexpandable collar 220, the expandable collar 220 may radially expandinto locking engagement with a downhole surface (e.g., with a casing).In the expanded state, a gap 238 may be formed between opposing angledsurfaces 239 a,b of the scarf cut 233. The angle 236 of the scarf cut233 may be calculated such that when the expandable collar 220 moves tothe expanded state, the opposing angled surfaces 239 a,b of the scarfcut 233 axially overlap to at least a small degree such that no axialgaps are created in the body 230. Accordingly, the one or more scarfcuts 233 may enable the expandable collar 220 to separate at theopposing angled surfaces 239 a,b and thereby enable a degree of freedomthat permits expansion and contraction of the expandable collar 220during operation. In certain embodiments, the first end 234 is movablerelative to the second end 235 as the expandable collar 220 expands. Incertain embodiments, the first end portion 234 rotates or otherwisemoves circumferentially relative to the second end 235 during expansion.In certain embodiments, the first end 234 converges and/or divergescircumferentially relative to the second end 235 during expansion.

One or more components of the zonal isolation device 200 such as thewedge 180, expansion ring 190, anchoring assembly 215, end element 170,and/or lower mandrel 163 may comprise a variety of materials including,but not limited to, a metal, a polymer, a composite material, and anycombination thereof. Suitable metals that may be used include, but arenot limited to, steel, brass, aluminum, magnesium, iron, cast iron,tungsten, tin, and any alloys thereof. Suitable composite materials thatmay be used include, but are not limited to, materials including fibers(chopped, woven, etc.) dispersed in a phenolic resin, such as fiberglassand carbon fiber materials.

In some embodiments, one or more components of the zonal isolationdevice 200 such as the sealing element 100, wedge 180, expansion ring190, anchoring assembly 215, end element 170, or lower mandrel 163 maybe made of a degradable or dissolvable material. The degradablematerials described herein may allow for time between setting a downholetool (e.g., a zonal isolation device) and when a particular downholeoperation is undertaken, such as a hydraulic fracturing treatmentoperation. In certain embodiments, degradable metal materials may allowfor acid treatments and acidified stimulation of a wellbore. In someembodiments, the degradable metal materials may require a large flowarea or flow capacity to enable production operations withoutunreasonably impeding or obstructing fluid flow while the zonalisolation device 200 degrades. As a result, production operations may beefficiently undertaken while the zonal isolation device 200 degrades andwithout creating significant pressure restrictions.

Degradable materials suitable for certain embodiments of the presentdisclosure include, but are not limited to borate glass, an aliphaticpolyester, polyglycolic acid (PGA), polylactic acid (PLA), polyvinylalcohol (PVA), a degradable rubber, a degradable polymer, agalvanically-corrodible metal, a dissolvable metal, a dehydrated salt,and any combination thereof. The degradable materials may be configuredto degrade by a number of mechanisms including, but not limited to,swelling, dissolving, undergoing a chemical change, electrochemicalreactions, undergoing thermal degradation, or any combination of theforegoing.

Degradation by swelling may involve the absorption by the degradablematerial of aqueous fluids or hydrocarbon fluids present within thewellbore environment such that the mechanical properties of thedegradable material degrade or fail. Hydrocarbon fluids that may swelland degrade the degradable material include, but are not limited to,crude oil, a fractional distillate of crude oil, a saturatedhydrocarbon, an unsaturated hydrocarbon, a branched hydrocarbon, acyclic hydrocarbon, and any combination thereof. Exemplary aqueousfluids that may swell to degrade the degradable material include, butare not limited to, fresh water, saltwater (e.g., water containing oneor more salts dissolved therein), brine (e.g., saturated salt water),seawater, acid, bases, or combinations thereof. In degradation byswelling, the degradable material may continue to absorb the aqueousand/or hydrocarbon fluid until its mechanical properties are no longercapable of maintaining the integrity of the degradable material and itat least partially falls apart. In some embodiments, the degradablematerial may be designed to only partially degrade by swelling in orderto ensure that the mechanical properties of a component of the zonalisolation device 200 formed from the degradable material is sufficientlycapable of lasting for the duration of the specific operation in whichit is utilized.

Degradation by dissolving may involve a degradable material that issoluble or otherwise susceptible to an aqueous fluid or a hydrocarbonfluid, such that the aqueous or hydrocarbon fluid is not necessarilyincorporated into the degradable material (as is the case withdegradation by swelling), but becomes soluble upon contact with theaqueous or hydrocarbon fluid. Degradation by undergoing a chemicalchange may involve breaking the bonds of the backbone of the degradablematerial (e.g., a polymer backbone) or causing the bonds of thedegradable material to crosslink, such that the degradable materialbecomes brittle and breaks into small pieces upon contact with evensmall forces expected in the wellbore environment. Thermal degradationof the degradable material may involve a chemical decomposition due toheat, such as the heat present in a wellbore environment. Thermaldegradation of some degradable materials mentioned or contemplatedherein may occur at wellbore environment temperatures that exceed about93° C. (or about 200° F.).

With respect to degradable polymers used as a degradable material, apolymer may be considered “degradable” if the degradation is due to, insitu, a chemical and/or radical process such as hydrolysis, oxidation,or UV radiation. Degradable polymers, which may be either natural orsynthetic polymers, include, but are not limited to, polyacrylics,polyamides, and polyolefins such as polyethylene, polypropylene,polyisobutylene, and polystyrene. Suitable examples of degradablepolymers that may be used in accordance with the embodiments includepolysaccharides such as dextran or cellulose, chitins, chitosans,proteins, aliphatic polyesters, poly(lactides), poly(glycolides),poly(ε-caprolactones), poly(hydroxybutyrates), poly(anhydrides),aliphatic or aromatic polycarbonates, poly(orthoesters), poly(aminoacids), poly(ethylene oxides), polyphosphazenes, poly(phenyllactides),polyepichlorohydrins, copolymers of ethylene oxide/polyepichlorohydrin,terpolymers of epichlorohydrin/ethylene oxide/allyl glycidyl ether, andany combination thereof. In certain embodiments, the degradable materialis polyglycolic acid or polylactic acid. In some embodiments, thedegradable material is a polyanhydride. Polyanhydride hydrolysis mayproceeds, in situ, via free carboxylic acid chain-ends to yieldcarboxylic acids as final degradation products. The erosion time may bevaried over a broad range of changes in the polymer backbone. Examplesof polyanhydrides suitable for certain embodiments of the presentdisclosure include, but are not limited to poly(adipic anhydride),poly(suberic anhydride), poly(sebacic anhydride), and poly(dodecanedioicanhydride). Other examples suitable for certain embodiments of thepresent disclosure include, but are not limited to poly(maleicanhydride) and poly(benzoic anhydride).

Degradable rubbers suitable for certain embodiments of the presentdisclosure include, but are not limited to degradable natural rubbers(i.e., cis-1,4-polyisoprene) and degradable synthetic rubbers, which mayinclude, but are not limited to, ethylene propylene diene M-classrubber, isoprene rubber, isobutylene rubber, polyisobutene rubber,styrene-butadiene rubber, silicone rubber, ethylene propylene rubber,butyl rubber, norbornene rubber, polynorbornene rubber, a block polymerof styrene, a block polymer of styrene and butadiene, a block polymer ofstyrene and isoprene, and any combination thereof. Other degradablepolymers suitable for certain embodiments of the present disclosureinclude those that have a melting point that is such that it willdissolve at the temperature of the subterranean formation in which it isplaced.

In some embodiments, the degradable material may have a thermoplasticpolymer embedded therein. The thermoplastic polymer may modify thestrength, resiliency, or modulus of a portion of the zonal isolationdevice 200 and may also control the degradation rate. Thermoplasticpolymers suitable for certain embodiments of the present disclosureinclude, but are not limited to an acrylate (e.g.,polymethylmethacrylate, polyoxymethylene, a polyamide, a polyolefin, analiphatic polyamide, polybutylene terephthalate, polyethyleneterephthalate, polycarbonate, polyester, polyethylene,polyetheretherketone, polypropylene, polystyrene, polyvinylidenechloride, styrene-acrylonitrile), polyurethane prepolymer, polystyrene,poly(o-methylstyrene), poly(m-methylstyrene), poly(p-methylstyrene),poly(2,4-dimethylstyrene), poly(2,5-dimethylstyrene),poly(p-tert-butylstyrene), poly(p-chlorostyrene), poly(α-methylstyrene),co- and ter-polymers of polystyrene, acrylic resin, cellulosic resin,polyvinyl toluene, and any combination thereof. Each of the foregoingmay further comprise acrylonitrile, vinyl toluene, or methylmethacrylate. The amount of thermoplastic polymer that may be embeddedin a degradable material may be any amount that confers a desirableelasticity without affecting the desired amount of degradation. In someembodiments, the thermoplastic polymer may be included in an amount inthe range of a lower limit of about 1%, 5%, 10%, 15%, 20%, 25%, 30%,35%, 40%, and 45% to an upper limit of about 91%, 85%, 80%, 75%, 70%,65%, 60%, 55%, 50%, and 45% by weight of the degradable material,encompassing any value or subset therebetween.

In certain embodiments, galvanically-corrodible metals may be used as adegradable material and may be configured to degrade via anelectrochemical process in which the galvanically-corrodible metalcorrodes in the presence of an electrolyte (e.g., brine or othersalt-containing fluids present within the wellbore).Galvanically-corrodible metals suitable for certain embodiments of thepresent disclosure include, but are not limited to tin, aluminum, zinc,and magnesium. Galvanically-corrodible metals may include anano-structured matrix. One example of a nano-structured matrixmicro-galvanic material is a magnesium alloy with iron-coatedinclusions. Galvanically-corrodible metals suitable for certainembodiments of the present disclosure include micro-galvanic metals ormaterials, such as a solution-structured galvanic material. An exampleof a solution-structured galvanic material is zirconium (Zr) containinga magnesium (Mg) alloy, where different domains within the alloy containdifferent percentages of Zr. This may lead to a galvanic couplingbetween these different domains, which causes micro-galvanic corrosionand degradation. Micro-galvanically corrodible magnesium alloys couldalso be solution-structured with other elements such as zinc, aluminum,nickel, iron, carbon, tin, silver, copper, titanium, rare earthelements, et cetera. Micro-galvanically corrodible aluminum alloys couldbe in solution with elements such as nickel, iron, carbon, tin, silver,copper, titanium, gallium, et cetera.

In some embodiments, blends of certain degradable materials may also besuitable as the degradable material for at least a portion of the zonalisolation device 200. One example of a suitable blend of degradablematerials is a mixture of PLA and sodium borate. Another example mayinclude a blend of PLA and boric oxide. The choice of blended degradablematerials may depend, at least in part, on the conditions of the well(e.g., wellbore temperature). For instance, lactides have been found tobe suitable for lower temperature wells, including those within therange of 60° F. to 150° F., and PLAs have been found to be suitable forwellbore temperatures above this range. In addition, PLA may be suitablefor higher temperature wells. Some stereoisomers of poly(lactide) ormixtures of such stereoisomers may be suitable for even highertemperature applications. Dehydrated salts may also be suitable forhigher temperature wells. Other blends of degradable materials mayinclude materials that include different alloys including using the sameelements but in different ratios or with a different arrangement of thesame elements.

In some embodiments, a degradable material may include a material thathas undergone different heat treatments and exhibits varying grainstructures or precipitation structures. As an example, in some magnesiumalloys, the beta phase can cause accelerated corrosion if it occurs inisolated particles. Homogenization annealing for various times andtemperatures causes the beta phase to occur in isolated particles or ina continuous network. In this way, the corrosion behavior may bedifferent for the same alloy with different heat treatments.

In some embodiments, all or a portion of the outer surface of at least aportion of the zonal isolation device 200 may be treated to impededegradation. For example, a surface of the zonal isolation device 200may undergo a treatment that aids in preventing the degradable material(e.g., a galvanically-corrodible metal) from galvanically-corroding.Treatments suitable for certain embodiments of the present disclosureinclude, but are not limited to, an anodizing treatment, an oxidationtreatment, a chromate conversion treatment, a dichromate treatment, afluoride anodizing treatment, a hard anodizing treatment, and anycombination thereof. Some anodizing treatments may result in an anodizedlayer of material being deposited on the surface. The anodized layer maycomprise materials such as, but not limited to, ceramics, metals,polymers, epoxies, elastomers, or any combination thereof and may beapplied using any suitable processes known to those of skill in the art.Examples of suitable processes that result in an anodized layer include,but are not limited to, soft anodize coating, anodized coating,electroless nickel plating, hard anodized coating, ceramic coatings,carbide beads coating, plastic coating, thermal spray coating, highvelocity oxygen fuel (HVOF) coating, a nano HVOF coating, a metalliccoating, and any combination thereof.

In some embodiments, all or a portion of an outer surface of the zonalisolation device 200 may be treated or coated with a substanceconfigured to enhance degradation of the degradable material. Forexample, such a treatment or coating may be configured to remove aprotective coating or treatment or otherwise accelerate the degradationof the degradable material of the zonal isolation device 200. In someembodiments, a galvanically-corroding metal material is coated with alayer of PGA. In this example, the PGA may undergo hydrolysis and causethe surrounding fluid to become more acidic, which may accelerate thedegradation of the underlying metal.

In some embodiments, the degradable material may be made of dissimilarmetals that generate a galvanic coupling that either accelerates ordecelerates the degradation rate of the zonal isolation device 200. Aswill be appreciated, such embodiments may depend on where the dissimilarmetals lie on the galvanic potential. In at least one embodiment, agalvanic coupling may be generated by embedding a cathodic substance orpiece of material into an anodic structural element. For instance, thegalvanic coupling may be generated by dissolving aluminum in gallium. Agalvanic coupling may also be generated by using a sacrificial anodecoupled to the degradable material. In such embodiments, the degradationrate of the degradable material may be decelerated until the sacrificialanode is dissolved or otherwise corroded away.

An embodiment of the present disclosure is a zonal isolation device,comprising: a tubular body having a fluid communication pathway formedalong a longitudinal axis comprising: a sealing element comprising adeformable material and an inner bore forming at least a portion of thefluid communication pathway; an expansion ring disposed within the boreof the sealing element; a wedge engaged with a downhole end of thesealing element; and an anchoring assembly engaged with the wedge.

In one or more embodiments described in the preceding paragraph, thetubular body further comprises an end element adjacent the anchoringassembly. In one or more embodiments described above, the sealingelement is radially expandable into sealing engagement with a downholesurface. In one or more embodiments described above, the anchoringassembly comprises a plurality of arcuate-shaped slip segments forlocking engagement with a downhole surface. In one or more embodimentsdescribed above, at least two of the plurality of arcuate-shaped slipsegments are interconnected by a shearable link. In one or moreembodiments described above, the shearable link shears upon axialexpansion. In one or more embodiments described above, longitudinalcompression of the tubular body radially expands the sealing element andradially expands the anchoring assembly. In one or more embodimentsdescribed above, the sealing element is coupled to the wedge and thewedge is coupled to the anchoring assembly. In one or more embodimentsdescribed above, the wedge is coupled to the sealing element by acompression fit, an interference fit, or a bonding agent.

Another embodiment of the present disclosure is a method comprising:inserting into a wellbore a zonal isolation device disposed on a settingtool adapter kit comprising a mandrel, wherein the zonal isolationdevice comprises: a sealing element comprising a deformable material andan inner bore; an expansion ring movably disposed within the inner boreof the sealing element; a wedge engaged with a downhole end of thesealing element; an anchoring assembly engaged with the wedge; and anend element adjacent the anchoring assembly and detachably coupled tothe mandrel; and actuating to pull upwardly on the mandrel, wherein theupward movement of the mandrel longitudinally compresses the zonalisolation device, causing the expansion ring to axially move relative tothe sealing element and radially expand the sealing element into asealing engagement with a downhole surface.

In one or more embodiments described in the preceding paragraph, theupward movement of the mandrel engages the anchoring assembly with thewedge, radially expanding the anchoring assembly into a lockingengagement with the downhole surface. In one or more embodimentsdescribed above, the method further comprises shearing a shear devicecoupling the mandrel to the end element. In one or more embodimentsdescribed above, the method further comprises removing the setting tooladapter kit and the mandrel from the wellbore. In one or moreembodiments described above, one or more components of the zonalisolation device comprises a pump-down ring. In one or more embodimentsdescribed above, the method further comprises seating a sealing ball onthe expansion ring. In one or more embodiments described above, theanchoring assembly comprises a plurality of arcuate-shaped slip segmentsfor locking engagement with the downhole surface. In one or moreembodiments described above, upon sufficient movement of the wedgerelative to the plurality of arcuate-shaped slip segments, at least twoof the plurality of arcuate-shaped slip segments slip segments areseparated from each other by shearing a shearable link joining the atleast two slip segments.

Another embodiment of the present disclosure is a zonal isolationsystem, comprising: a setting tool adapter kit comprising a mandrel; asealing element disposed on the mandrel for sealing engagement with adownhole surface; an expansion ring movably disposed on the mandrel andengaged with the sealing element; a wedge disposed on the mandrel; andan anchoring assembly disposed around the mandrel for locking engagementwith a downhole surface.

In one or more embodiments described in the preceding paragraph, thesystem further comprises an end element coupled to the mandrel. In oneor more embodiments described in the preceding sentence, the end elementis detachably coupled to the mandrel by a shearing element.

Referring to FIG. 16, a zonal isolation device 200 is employed in awellbore system 300 according to certain embodiments of the presentdisclosure. A wellbore system 300 for sealing a zonal isolation devicein a wellbore includes a service rig 110 extending over and around awellbore 120. The service rig 110 may comprise a drilling rig, acompletion rig, a workover rig, or the like. In some embodiments, theservice rig 110 may be omitted and replaced with a standard surfacewellhead completion or installation, without departing from the scope ofthe disclosure. The wellbore 120 is within a subterranean formation 150and has a casing 130 lining the wellbore 120, the casing 130 held intoplace by cement 122. In some embodiments, the wellbore casing 130 may beomitted from all or a portion of the wellbore 120 and the principles ofthe present disclosure may alternatively apply to an “open-hole”environment. Although shown as vertical, the wellbore 120 may includehorizontal, vertical, slant, curved, and other types of wellbore 120geometries and orientations. As depicted, the zonal isolation device 200may include a tubular body 205 comprising a sealing element 100, a wedge180, an anchoring assembly 215, and an end element 170 such as a muleshoe or the like. The zonal isolation device 200 may be coupled to asetting tool adapter kit 160 (also referred to as a setting toolassembly) for conveyance into the wellbore and setting. The setting tooladapter kit 160 may comprise a mandrel that may engage with the zonalisolation device 200. In embodiments, the setting tool adapter kit 160may be coupled to one or more perforating guns 310 typically locateduphole from the setting tool adapter kit 160. The zonal isolation device200, the setting tool adapter kit 160, and the perforation guns 310 maybe moved down the wellbore 120 via a conveyance 140 that extends fromthe service rig 110 to a target location. The conveyance 140 can be, forexample, tubing-conveyed, wireline, slickline, work string, or any othersuitable means for conveying zonal isolation devices into a wellbore. Incertain embodiments, the conveyance 140 may be coupled to theperforating guns 310 that are coupled to the setting tool adapter kit160 that is coupled to the zonal isolation device 200. As analternative, in some embodiments, a conveyance 140 is not used and theentire zonal isolation device 200 is pumped to location as an untethereddevice. As depicted in FIG. 16, the setting tool is an internal settingtool, but an external setting tool could be used in one or moreembodiments of the present disclosure. Examples of suitable settingtools for certain embodiments of the present disclosure include, but arenot limited to Baker 10, Baker 20, 3½ HES GO, and the like, or any othersuitable setting tool. In some embodiments, the zonal isolation device200 may be pumped to the target location using hydraulic pressureapplied from the service rig 110. For example in an embodiment as shownin FIG. 16, the conveyance 140 is a wireline that allows the zonalisolation device 200 and associated setting tool adapter kit 160 andperforating guns 310 to be pumped through the wellbore to a desiredlocation (e.g., proximate a zone to be perforated and fractured). Insuch embodiments, the conveyance 140 serves to maintain control of thezonal isolation device 200 as it traverses the wellbore 120 and providesthe necessary power to actuate and set the zonal isolation device 200upon reaching the target location. In other embodiments, the zonalisolation device 200 freely falls to the target location under the forceof gravity. Upon reaching the target location, the zonal isolationdevice 200 may be actuated or “set” and thereby provide a point of fluidisolation within the wellbore 120. Setting may occur by longitudinalcompression of the tubular body 205, which may move the sealing element100 into sealing engagement with one or more downhole surfaces, and mayalso move the anchoring assembly 215 into locking engagement with one ormore downhole surfaces (e.g., an interior surface of casing 130). Aftersetting, the setting tool adapter kit 160 may disengage from the zonalisolation device 200 and be withdrawn from the wellbore 120.

In FIG. 16, the zonal isolation device 200 is depicted in an unsetconfiguration, and the perforating guns 310 have not fired. In the unsetconfiguration, the anchoring assembly 215 is configured such that thezonal isolation device can be moved uphole or downhole without catchingon the casing 130 of the wellbore 120. Once the zonal isolation device200 reaches the desired location, the setting tool adapter kit 160 maybe actuated (e.g., by the setting tool) to set the zonal isolationdevice 200, anchoring it into place and moving it into a sealingengagement. Then the perforating guns 310 may fire to createperforations in the casing and surrounding formation adjacent thewellbore wall. Prior to firing, the perforating guns 310 may be moved(e.g., uphole) a distance from the set zonal isolation device, ifdesired. It should be noted that while FIG. 16 generally depicts aland-based operation, the principles described herein are equallyapplicable to operations that employ floating or sea-based platforms andrigs, without departing from the scope of the disclosure. It should alsobe noted that a plurality of sets of perforating guns 310 and zonalisolation devices 200 may be placed in the wellbore 120. In someembodiments, for example, two or more sets of perforating guns 310 andzonal isolation devices 200 may be arranged in the wellbore 120 todivide the wellbore 120 into smaller intervals or “zones” for aparticular operation (e.g., hydraulic stimulation).

Referring to FIG. 17, an x-y-z coordinate system is illustrated, whereina left side and a right side are along a first or x-axis, the centralaxis 405 of the zonal isolation device 200 is along a second or y-axis,wherein the y-axis is in the same plane as and perpendicular to thex-axis, and a front side and a back side are along a z-axis, wherein thez-axis is along a plane perpendicular to the plane of the x-axis and they-axis. Unless otherwise indicated, the x-y-z coordinate system appliesto FIGS. 17, 18A, 18B, 19, 20A, 20B, 21, and 22.

In embodiments, as depicted in FIG. 17, the zonal isolation device 200comprises: a sealing element 100 comprising a deformable material and aninner bore 105; a support ring 190 movably disposed within the innerbore 105 of the sealing element 100; a rotatable sealing component 400directly or indirectly connected to the uphole end of the support ring190, wherein the rotatable sealing component blocks fluid flow throughthe zonal isolation device 200 in a closed position and allows fluidflow through the zonal isolation device 200 in an open position andwherein a mandrel 161 of a setting tool is engaged with and holds therotatable sealing component 400 in the open position while the zonalisolation device 200 is inserted into the wellbore as shown in FIG. 21;a wedge 180 engaged with a downhole end of the sealing element 100; ananchoring assembly 215 engaged with the wedge 180; and an end element170 (e.g., a mule shoe) adjacent the anchoring assembly 215 anddetachably coupled to the mandrel 161 of the setting tool. The supportring may also be referred to as a frustum having a conical shape, and itshould be noted that support ring 190 of FIGS. 16-22 is similar toexpansion ring 190 of FIGS. 1-15, with the further understanding thatsupport ring 190 further supports the rotatable sealing component 400 asdescribed herein.

In embodiments, the rotatable sealing component 400 of the zonalisolation device 200 can be selected from a group consisting of aflapper valve (comprising a flapper 425 as shown in FIGS. 17, 21, and22), dual flappers, a ball valve (comprising a ball 450 having a bore asshown in FIGS. 18A and 18B), an iris valve (comprising an iris diaphragm475 as shown in FIGS. 19, 20A, and 20B), and a pinch valve.

In embodiments, the rotatable sealing component 400 remains at anaxially fixed distance from the support ring 190 as a result ofattachment of the rotatable sealing component 400 to the support ring190 such that they move together (e.g., as an integrated or unifiedcomponent) in an axial direction during setting of the zonal isolationdevice 200, which is further illustrated by the relative positioning ofthe rotatable sealing component 400 to the support ring 190 in the unsetconfiguration of FIG. 21 and the set configuration of FIG. 22.

As depicted in FIG. 17, the zonal isolation device 200 comprises arotatable sealing component 400 that around a pivot axis (e.g., parallelto the z-axis) that is perpendicular to the central axis 405 (e.g., they-axis) and is tangential to an outer radius of the support ring 190,the outer radius of the support ring extending from the central axis 405to an outer edge of the support ring and wherein upon rotation a contactsurface of the rotatable sealing component 400 contacts a sealingsurface (e.g., face or seat) of the support ring 190. In embodiments,the rotatable sealing component 400 comprises a flapper 425. Inembodiments, the flapper 425 is rotatably connected to the uphole end ofsupport ring 190 via a hinge 426, wherein the hinge 426 comprises thepivot axis (e.g., parallel to the z-axis), and upon rotation of theflapper 425 via the hinge 426 the flapper 425 contacts the sealingsurface (e.g., face or seat) of the support ring 190 thereby forming aseal that provides the closed position. In embodiments, the flapper 425is biased in the closed position by a spring 427. In embodiments, thespring 427 is a torsion spring (e.g., a flat spiral spring or a clockspring). In embodiments, as depicted in FIG. 17, the flapper 425 isbiased in at least a partially closed position during and/or afteractuation (e.g., setting) of the zonal isolation device 200. In anaspect, the flapper 425 is biased in at least a partially closedposition by contact with sealing element 100 upon setting of the zonalisolation device. In embodiments, the pumping fluid from the surfacedown the wellbore provides a further closing force on the flapper 425such that the flapper 425 transitions to or remains in a fully closedposition, wherein an end of the flapper 425 opposite the hinged endcontacts the sealing surface and blocks fluid flow through the zonalisolation device 200. In other words, downhole fluid flow helps to closethe flapper, if needed.

In embodiments, as depicted in FIG. 21, a setting sleeve 167 is disposedaround the mandrel 161 further comprises a rotation restrictor 439(e.g., a latch or groove) that engages a flapper end 432 of the flapper425 opposite a hinged end of the flapper 425 to hold to flapper 425 inplace in the open position and protect/shield the flapper 425 duringrun-in (e.g., pumping) of the zonal isolation device 200 into thewellbore, wherein upon removal of the mandrel the rotatable sealingcomponent transitions to the fully closed position.

In embodiments, as depicted in FIGS. 18A and 18B, the zonal isolationdevice 200 comprises a rotatable sealing component 400 that rotatesaround a pivot axis 460 (e.g., x-axis) that is about perpendicular withand about intersects the central axis 405 (e.g., y-axis) and wherein acontact surface of the rotatable sealing component 400 contacts asealing surface (e.g., face or seat) of the support ring 190.

In embodiments, as depicted in FIGS. 18A and 18B, the rotatable sealingcomponent 400 comprises a ball 450 having a bore 451 passing through theball 450, and wherein a central axis of the bore 451 is about coaxialwith the central axis 405 when the zonal isolation device 200 in an openposition (FIG. 18A) and wherein the central axis of the bore 451 isabout perpendicular with (e.g., z-axis) and about intersects the centralaxis 405 when the zonal isolation device 200 is in the closed position(FIG. 18B).

In embodiments as illustrated in FIGS. 18A and 18B, the zonal isolationdevice 200 further comprises a ball housing 452 connected to (orintegral with) an uphole portion of the support ring 190, wherein theball is rotatably disposed within the ball housing 452. In embodiments,the ball 450 further comprise two pins 453 positioned on opposite sidesof the ball 450, wherein the pins are coaxial with the pivot axis 460(e.g., x-axis) and wherein the pins 453 engage corresponding grooves onopposite interior surfaces of the ball housing 452 and wherein uponrotation of the ball 450 via the pins 453 a contact surface of the ballcontacts the sealing surface (e.g., face or seat) of the support ring190 thereby forming a seal that provides the closed position (FIG. 18B).In embodiments, as illustrated in FIGS. 18A and 18B, the ball 450 isbiased in the closed position by a spring 427. In embodiments, thespring 427 is a torsion spring (e.g., a flat spiral spring or a clockspring). During run-in (e.g., pumping) of the zonal isolation device 200into the wellbore, the biased ball 450 can be held in the open positionby mandrel 161 of the setting tool, similar to the configuration shownin FIG. 21 for a flapper valve, wherein upon removal of the mandrel therotatable sealing component transitions to the fully closed position.

In embodiments, as depicted in FIGS. 19, 20A, and 20B, the zonalisolation device 200 comprises a rotatable sealing component 400 thatrotates around a pivot axis 460 that is parallel to and about coaxialwith the central axis 405 (e.g., y-axis).

Referring to FIGS. 19, 20A, and 20B, in embodiments, the rotatablesealing component 400 comprises an iris diaphragm 475, wherein the irisdiaphragm 475 rotates clock-wise or counter-clockwise about the pivotaxis (e.g., y-axis) to transition between the open (FIG. 20A) and closed(FIG. 20B) positions. In embodiments, the iris diaphragm 475 furthercomprises a plurality of blades 477 connected to a base plate 480 by acorresponding plurality of actuating arms 478. In embodiments, therotatable sealing component 400 further comprises a cylindrical irisdiaphragm housing 476 connected to an uphole portion of the support ring190, wherein the iris diaphragm 475 is rotatably disposed within thecylindrical iris diaphragm housing 476 between the open and closedpositions. In embodiments, the uphole portion of the support ring 190further comprises a cylindrical groove 483 along an inner surfacethereof, wherein the cylindrical iris diaphragm housing 476 is disposedwithin the cylindrical groove 483. In embodiments, the rotatable sealingcomponent 400 further comprises a control arm 481 located in a controlgroove 483 of the base plate 480 such that clockwise or counterclockwisemovement of the control arm 481 about the pivot axis 460 transitions theiris diaphragm 475 between the open and closed positions. Inembodiments, the iris diaphragm 475 is biased in the closed position bya spring 479 applying a force to the control arm 481, wherein the springis a helical compression spring located in the control groove 483. Inembodiments, the rotatable sealing component 400 is biased to the closedposition by application of a closing force by a biasing mechanism, whichmay be for example a pre-tensioned spring or pre-pressured hydraulicpiston. During run-in (e.g., pumping) of the zonal isolation device 200into the wellbore, the biased iris diaphragm 475 can be held in the openposition by mandrel 161 of the setting tool, similar to theconfiguration shown in FIG. 21 for a flapper valve, wherein upon removalof the mandrel the rotatable sealing component transitions to the fullyclosed position.

In embodiments as shown in FIGS. 16-22, the zonal isolation device 200does not comprise a mandrel 161, which can provide increased surfacearea for contact of one or more dissolvable components of the zonalisolation device 200 with a wellbore fluid. In embodiments, as depictedin FIG. 22, the end element 170 (e.g., mule shoe) detaches from themandrel 161 upon actuation (e.g., setting) of the zonal isolation device200, thereby providing increased surface area for contact of one or moredissolvable components of the zonal isolation device 200 with a wellborefluid.

In embodiments as shown in FIGS. 16-22, the sealing element 100comprises a metallic deformable material. In embodiments, the sealingelement 100 further comprises a contact surface that contacts an innersurface of the wellbore (e.g., casing) upon actuation (e.g., setting) ofthe zonal isolation device 200 and wherein the contact surface comprisesa non-metallic deformable material (e.g., polymer, elastomer, plastic,rubber, etc.).

Referring to FIGS. 17, 18A, 18B, 19, and 21, disclosed herein is a zonalisolation system, comprising: a setting tool adapter kit comprising amandrel 161; a sealing element 100 comprising a deformable material andan inner bore 105, the sealing element 100 disposed on the mandrel 161for sealing engagement with a downhole surface; an support ring movablydisposed on the mandrel and engaged with the sealing element; arotatable sealing component 400 directly or indirectly connected to theuphole end of the support ring 190, wherein the rotatable sealingcomponent blocks fluid flow through the zonal isolation device 200 in aclosed position and allows fluid flow through the zonal isolation device200 in an open position and wherein the mandrel 161 is engaged with andholds the rotatable sealing component 400 in the open position while thezonal isolation device 200 is inserted into the wellbore; a wedge 180disposed on the mandrel 161 and engaged with a downhole end of thesealing element 100; and an anchoring assembly 215 disposed on themandrel and engaged with the wedge 180 for locking engagement with adownhole surface. In embodiments, the system further comprises an endelement 170 adjacent the anchoring assembly 215 and coupled to themandrel 161. In embodiments, the end element 170 can detachably coupledto the mandrel 161 by a shearing element.

Referring to FIG. 21, disclosed herein is a method (e.g., a method ofhydraulic fracturing) comprising: inserting into a wellbore a zonalisolation device 200 having a central axis 405 and disposed on a settingtool adapter kit 160 comprising a mandrel 161; pulling upwardly on themandrel 161 to actuate the zonal isolation device 200, wherein theupward movement of the mandrel 161 longitudinally compresses the zonalisolation device 200, causing the support ring 190 to axially moverelative to the sealing element 100 and radially expand the sealingelement 100 into a sealing engagement with a downhole surface (e.g.,casing 130); allowing the rotatable sealing component 400 to rotate fromthe open position to the closed position upon removal of the mandrel 161from engagement with the rotatable sealing component 400, whereby awellbore zone below the zonal isolation device is isolated from fluidflow from a wellbore zone above the zonal isolation device; if notalready perforated with a plurality of perforations, perforating thecasing and surrounding formation with a plurality of perforations in thewellbore zone above the zonal isolation device; and pumping fluid (e.g.,a fracturing fluid such as a slickwater, a gel fluid, a proppant-ladenfluid) from the surface down the wellbore and into the formation via theplurality of perforations in the wellbore zone above the zonal isolationdevice and fracturing the formation, wherein a sealing device such as aball is not required to be pumped from the surface in order to preventfluid flow through the zonal isolation device 200 and divert the fluidinto the perforations and surrounding formation. Upon completion ofsetting/actuating, and removal of the mandrel 161, the set zonalisolation device 200 is as shown in FIG. 22.

In embodiments, the method as disclosed herein employs a zonal isolationdevice 200 comprising: a sealing element 100 comprising a deformablematerial and an inner bore 105; an support ring 190 (also referred to asa frustum having a conical shape) movably disposed within the inner bore105 of the sealing element 100; a rotatable sealing component 400directly or indirectly connected to the uphole end of the support ring190, wherein the rotatable sealing component blocks fluid flow throughthe zonal isolation device 200 in a closed position and allows fluidflow through the zonal isolation device 200 in an open position andwherein a mandrel 161 of a setting tool is engaged with and holds therotatable sealing component 400 in the open position while the zonalisolation device 200 is inserted into the wellbore; a wedge 180 engagedwith a downhole end of the sealing element 100; an anchoring assembly215 engaged with the wedge 180; and an end element 170 (e.g., a muleshoe) adjacent the anchoring assembly 215 and detachably coupled to themandrel 161.

Referring to FIGS. 23-27, in embodiments, the zonal isolation device 200comprises a flapper coupled to and supported by a support ring 190. Inembodiments, the zonal isolation device 200 with a flapper coupled toand supported by a support ring 190 can comprise: a sealing element 100comprising a deformable material and an inner bore 105; a support ring190 (also referred to as a frustum having a conical shape) movablydisposed within the inner bore 105 of the sealing element 100; a flapperconnected to an uphole end of the support ring 190 and configured toengage a sealing surface (e.g., face or seat) of support ring 190,wherein the flapper blocks fluid flow through the zonal isolation device200 in a fully closed position, allows unrestricted fluid flow throughthe zonal isolation device 200 in a fully open position, and allowsrestricted fluid flow through the zonal isolation device 200 when heldby a propping component (also referred to as a propping member) in anintermediate or partially open position; a wedge 180 engaged with adownhole end of the sealing element 100; an anchoring assembly 215engaged with the wedge 180; and an end element 170 (e.g., a mule shoe)adjacent the anchoring assembly 215.

Referring to FIGS. 23-27, in embodiments, the zonal isolation device 200can be a zonal isolation device with a flapper coupled to and supportedby a mandrel. In embodiments, the zonal isolation device with a flappercoupled to and supported by a mandrel can comprise: a mandrel having abore extending axially there through; an anchoring assembly (e.g., slip)circumferentially disposed about the mandrel and configured to expandand engage with a downhole surface; a sealing element circumferentiallydisposed about the mandrel and configured to compress and create a sealwith the downhole surface; and a flapper coupled to the mandrel andconfigured to engage a sealing surface (e.g., face or seat) of an end ofthe mandrel and seal the bore of the mandrel, wherein the flapper blocksfluid flow through the zonal isolation device in a fully closedposition, allows unrestricted fluid flow through the zonal isolationdevice in a fully open position, and allows restricted fluid flowthrough the zonal isolation device when held by a propping component(also referred to as a propping member) in an intermediate or partiallyopen position.

The embodiments shown in FIGS. 23-27 are applicable to either a zonalisolation device with a flapper coupled to and supported by a supportring or a zonal isolation device with a flapper coupled to and supportedby a mandrel. In the following description, a “zonal isolation device”can be referred to as either a zonal isolation device with flapper on asupport ring or a zonal isolation device with flapper on a mandrel.

In embodiments, as shown in FIGS. 25 and 26, flapper 425 is proppedpartially open (e.g., in an intermediate position) via a proppingcomponent, wherein the propping component comprises a spring (e.g.,spring 427 and/or spring 445). In embodiments as shown in FIG. 25, thespring is a torsion spring 427 (e.g., a flat spiral spring or a clockspring), wherein the torsion spring is positioned adjacent a hinged endof the flapper and wherein the torsion spring holds the flapper in theintermediate position when the torsion spring is in a neutral orequilibrium (e.g., non-compressed and non-stretched) state/condition,thereby allowing fluid flow via a gap formed between flapper end 432 andthe sealing surface as indicated by flow arrow 446. In embodiments asshown in FIG. 26, the spring is a coil spring 445, wherein a first endof the coil spring is received within a recess 441 in the uphole end ofthe support ring 190 and a second end of the coil spring 445 contactsflapper end 432, wherein the coil spring holds the flapper in theintermediate position when the coil spring is in a neutral orequilibrium (e.g., non-compressed and non-stretched) state/condition,thereby allowing fluid flow via a gap formed between flapper end 432 andthe sealing surface as indicated by flow arrow 446.

In embodiments, as shown in FIG. 27, flapper 425 is propped partiallyopen (e.g., in an intermediate position) via a propping component,wherein the propping component comprises a strut 448. In embodiments, afirst end of the strut 448 is received within a recess 441 in the upholeend of the support ring 190 and a second end of the strut 448 contactsflapper end 432, wherein the strut holds the flapper in the intermediateposition, thereby allowing fluid flow via a gap formed between flapperend 432 and the sealing surface as indicated by flow arrow 446. Inembodiments, the strut comprises a dissolvable material, a degradablematerial, an erodible material, an abradable material, atemperature-sensitive material (e.g., a fusible alloy), a corrodiblematerial, a frangible material, or combinations thereof and isconfigured such that the strut loses structural integrity when subjectedto contact with a wellbore fluid (e.g., downhole fluid flow), downholeambient conditions (e.g., temperature and/or pressure), or both, therebyallowing the flapper to transition from the intermediate position to thefully closed position.

In embodiments, as shown in FIG. 23, the flapper further comprises arupture disk 435 (also referred to as a burst disk or burst diaphragm),which optionally may be protected by one or more coating layers 437. Thecoating layers 437 are for protection only and do not preventapplication of pressure on the rupture disk or otherwise hinderoperation of the rupture disk. In embodiments, the rupture disk 435 isdisposed within a circumferential groove on an interior face of a holepassing through the flapper. The flapper with rupture disk as shown inFIG. 23 may be incorporated with any other embodiment herein referencinguse of a flapper, including without limitation the embodiments as shownin any of FIGS. 16, 17, and 21-27.

In embodiments, as shown in FIG. 24, the flapper further comprises areleasable hinge configured to decouple an end of the flapper proximatethe releasable hinge. In embodiments, the releasable hinge comprises apivot pin and wherein the end of the flapper proximate the releasablehinge comprises a u-shaped recess 438 receiving the pivot pin and a clip442 (e.g., a pinch clip) engaging the pivot pin, wherein the flapper isconfigured to decouple from the releasable hinge via application of areleasing force sufficient to overcome a retaining force applied to thereleasable hinge by the clip 442, for example a releasing force appliedvia flow of wellbore fluid as represented by flow arrows 440. Theflapper with releasable hinge as shown in FIG. 24 may be incorporatedwith any other embodiment herein referencing use of a flapper, includingwithout limitation the embodiments as shown in any of FIGS. 16, 17, and21-27.

Referring to FIG. 23, in embodiments, a zonal isolation device 200 witha flapper coupled to and supported by a support ring 190 comprises: asealing element 100 comprising a deformable material and an inner bore105; a support ring 190 (also referred to as a frustum having a conicalshape) movably disposed within the inner bore 105 of the sealing element100; a flapper connected to an uphole end of the support ring 190 andconfigured to engage a sealing surface (e.g., face or seat) of supportring 190, wherein the flapper blocks fluid flow through the zonalisolation device 200 in a fully closed position and allows unrestrictedfluid flow through the zonal isolation device 200 in a fully openposition and wherein the flapper further comprises a rupture disk 435(also referred to as a burst disk or burst diaphragm), which optionallymay be protected by one or more coating layers 437; a wedge 180 engagedwith a downhole end of the sealing element 100; an anchoring assembly215 engaged with the wedge 180; and an end element 170 (e.g., a muleshoe) adjacent the anchoring assembly 215.

Referring to FIG. 23, in embodiments, a zonal isolation device with aflapper coupled to and supported by a mandrel comprises: a mandrelhaving a bore extending axially there through; an anchoring assembly(e.g., slip) circumferentially disposed about the mandrel and configuredto expand and engage with a downhole surface; a sealing elementcircumferentially disposed about the mandrel and configured to compressand create a seal with the downhole surface; and a flapper coupled tothe mandrel and configured to engage a sealing surface (e.g., face orseat) of an end of the mandrel and seal the bore of the mandrel, whereinthe flapper blocks fluid flow through the zonal isolation device in afully closed position and allows unrestricted fluid flow through thezonal isolation device in a fully open position and wherein the flapperfurther comprises a rupture disk 435 (also referred to as a burst diskor burst diaphragm), which optionally may be protected by one or morecoating layers 437.

In embodiments, the zonal isolation device in FIG. 23 as disclosedherein, wherein the rupture disk is disposed within a circumferentialgroove on an interior face of a hole passing through the flapper.

Referring to FIG. 24, in embodiments, the zonal isolation device 200with a flapper coupled to and supported by a support ring 190 comprises:a sealing element 100 comprising a deformable material and an inner bore105; a support ring 190 (also referred to as a frustum having a conicalshape) movably disposed within the inner bore 105 of the sealing element100; a flapper connected to an uphole end of the support ring 190 andconfigured to engage a sealing surface (e.g., face or seat) of supportring 190, wherein the flapper blocks fluid flow through the zonalisolation device 200 in a fully closed position and allows unrestrictedfluid flow through the zonal isolation device 200 in a fully openposition and wherein the flapper further comprises a releasable hingeconfigured to decouple an end of the flapper proximate the releasablehinge; a wedge 180 engaged with a downhole end of the sealing element100; an anchoring assembly 215 engaged with the wedge 180; and an endelement 170 (e.g., a mule shoe) adjacent the anchoring assembly 215.

Referring to in FIG. 24, in embodiments, the zonal isolation device witha flapper coupled to and supported by a mandrel comprises: a mandrelhaving a bore extending axially there through; an anchoring assembly(e.g., slip) circumferentially disposed about the mandrel and configuredto expand and engage with a downhole surface; a sealing elementcircumferentially disposed about the mandrel and configured to compressand create a seal with the downhole surface; and a flapper coupled tothe mandrel and configured to engage a sealing surface (e.g., face orseat) of an end of the mandrel and seal the bore of the mandrel, whereinthe flapper blocks fluid flow through the zonal isolation device in afully closed position and allows unrestricted fluid flow through thezonal isolation device in a fully open position and wherein the flapperfurther comprises a releasable hinge configured to decouple an end ofthe flapper proximate the releasable hinge.

In embodiments, the zonal isolation device in FIG. 24 as disclosedherein, wherein the releasable hinge comprises a pivot pin and whereinthe end of the flapper proximate the releasable hinge comprises au-shaped recess 438 receiving the pivot pin and a clip 442 (e.g., apinch clip) engaging the pivot pin, wherein the flapper is configured todecouple from the releasable hinge via application of a releasing forcesufficient to overcome a retaining force applied to the releasable hingeby the clip 442, for example a releasing force applied via flow ofwellbore fluid as represented by flow arrows 440.

Disclosed herein is a method (e.g., a method of hydraulic fracturing)comprising: inserting into a cased wellbore the zonal isolation device(e.g., a zonal isolation device with a flapper coupled to and supportedby a support ring or a zonal isolation device with a flapper coupled toand supported by a mandrel) with a propping component as disclosedherein (e.g., a flapper propped open as shown in any of FIGS. 25-27);actuating the zonal isolation device to provide a set zonal isolationdevice; detaching a setting tool assembly from the set zonal isolationdevice; moving the setting tool assembly uphole from the set zonalisolation device, wherein the setting tool assembly is coupled to one ormore perforating guns located uphole from the setting tool assembly;sending a trigger signal to the one or more perforating guns; and uponfailure of at least one of the perforating guns to fire, pumping one ormore replacement perforating guns down the wellbore to a desiredlocation, wherein during the pumping the propping component (as shown inany of FIGS. 25-27) holds the flapper in the intermediate position andprovides for restricted flow of a wellbore fluid through the zonalisolation device.

In embodiments, the method as disclosed herein further comprises:sending a trigger signal to the one or more replacement perforatingguns; and forming a plurality of perforations through the casing andinto the surrounding formation in a wellbore zone located above the setzonal isolation device. In embodiments, the method further comprises:removing the setting tool assembly, the one or more perforating gunscoupled to the setting tool assembly, and the one or more replacementperforating guns from the wellbore.

Referring to FIG. 27, in embodiments, the method further comprises:structurally compromising the propping component 448 such that theflapper 425 can transition to the fully closed position, whereby awellbore zone below the set zonal isolation device is isolated fromfluid flow from the wellbore zone above the set zonal isolation device.

In embodiments, the propping component 448 comprises a degradablematerial, an erodible material, or an abradable material and isstructurally compromised via contact with a flowing wellbore fluid thatremoves all or a portion of the degradable material, the erodiblematerial, or the abradable material.

In embodiments, the propping component 448 comprises a dissolvablematerial or a corrodible material and is structurally compromised viacontact with a wellbore fluid (e.g., via chemical decomposition of thestrut, dissolution of the strut, etc.).

In embodiments, the propping component 448 comprises atemperature-sensitive material (e.g., a fusible alloy) and isstructurally compromised via change in ambient temperature in thewellbore proximate the set zonal isolation plug. In embodiments, thechange in ambient temperature is controlled by adjusting (e.g., halting)a flow of fluid in the wellbore, thereby allowing the temperature in thewellbore proximate the set zonal isolation plug to increase and softenthe temperature-sensitive material.

In embodiments, the propping component 448 comprises a frangiblematerial and is structurally compromised via contact with a pressurewave. In embodiments, the pressure wave is produced via a fluid pulsefrom the surface or from firing of a perforating gun (e.g., a shockwave).

Referring to FIGS. 25 and 26, in embodiments, the method as disclosedherein, after removing the setting tool assembly, the one or moreperforating guns coupled to the setting tool assembly, and the one ormore replacement perforating guns from the wellbore, the method furthercomprises: applying a closing force on the flapper that is greater thana spring force applied by spring 427 and/or spring 445 to transition theflapper from the intermediate position to the fully closed position,wherein the closing force results from contact with fluid flowing intothe wellbore.

In embodiments, the method as disclosed herein referring to FIGS. 25-27,further comprises pumping fluid (e.g., a fracturing fluid such as aslickwater, a gel fluid, a proppant-laden fluid) from the surface downthe wellbore and into the formation via the plurality of perforations inthe wellbore zone above the set zonal isolation device and fracturingthe formation, wherein a sealing device such as a ball is not requiredto be pumped from the surface in order to prevent fluid flow through thezonal isolation device and divert the fluid into the perforations andsurrounding formation. In embodiments, the flapper comprises a rupturedisk, and the method further comprises rupturing the rupture disk toprovide for fluid flow through the set zonal isolation device, whereinthe fluid flow enhances the dissolution rate of one or more dissolvablecomponents of the zonal isolation device. In embodiments, the flappercomprises a releasable hinge, and the method further comprisesdecoupling an end of the flapper proximate the releasable hinge toremove the flapper from contact with the sealing surface to provide forfluid flow through the set zonal isolation device, wherein the fluidflow enhances the dissolution rate of one or more dissolvable componentsof the zonal isolation device.

Also, disclosed herein is a method (e.g., a method of hydraulicfracturing) comprising: inserting into a cased wellbore the zonalisolation device with a propping component as disclosed herein (e.g., aflapper propped open as shown in any of FIGS. 25-27); actuating thezonal isolation device to provide a set zonal isolation device;detaching a setting tool assembly from the set zonal isolation device;moving the setting tool assembly uphole from the set zonal isolationdevice, wherein the setting tool assembly is coupled to one or moreperforating guns located uphole from the setting tool assembly; sendinga trigger signal to the one or more perforating guns; forming aplurality of perforations through the casing and into the surroundingformation in a wellbore zone located above the set zonal isolationdevice; removing the setting tool assembly and the one or moreperforating guns coupled to the setting tool assembly from the wellbore;either (i) as in FIG. 27, structurally compromising the proppingcomponent such that the flapper can transition to the fully closedposition, whereby a wellbore zone below the set zonal isolation deviceis isolated from fluid flow from the wellbore zone above the set zonalisolation device, wherein the propping component is structurallycompromised or (ii) as in FIGS. 25-26, applying a closing force on theflapper that is greater than a spring force applied by spring 427 and/orspring 445 to transition the flapper from the intermediate position tothe fully closed position, wherein the closing force results fromcontact with fluid flowing into the wellbore; and pumping fluid (e.g., afracturing fluid such as a slickwater, a gel fluid, a proppant-ladenfluid) from the surface down the wellbore and into the formation via theplurality of perforations in the wellbore zone above the set zonalisolation device and fracturing the formation, wherein a sealing devicesuch as a ball is not required to be pumped from the surface in order toprevent fluid flow through the zonal isolation device and divert thefluid into the perforations and surrounding formation. In embodiments,the flapper comprises a rupture disk as in FIG. 23, and the methodfurther comprises rupturing the rupture disk to provide for fluid flowthrough the set zonal isolation device, wherein the fluid flow enhancesthe dissolution rate of one or more dissolvable components of the zonalisolation device. In embodiments, the flapper comprises a releasablehinge as in FIG. 24, and the method further comprises decoupling an endof the flapper proximate the releasable hinge to remove the flapper fromcontact with the sealing surface to provide for fluid flow through theset zonal isolation device, wherein the fluid flow enhances thedissolution rate of one or more dissolvable components of the zonalisolation device.

Referring to FIG. 23, disclosed herein is a method (e.g., a method ofhydraulic fracturing) comprising: inserting into a cased wellbore thezonal isolation device; actuating the zonal isolation device to providea set zonal isolation device, wherein the flapper transitions to thefully closed position and a wellbore zone below the set zonal isolationdevice is isolated from fluid flow from a wellbore zone above the setzonal isolation device; detaching a setting tool assembly from the setzonal isolation device; moving the setting tool assembly uphole from theset zonal isolation device, wherein the setting tool assembly is coupledto one or more perforating guns located uphole from the setting toolassembly; sending a trigger signal to the one or more perforating guns;forming a plurality of perforations through the casing and into thesurrounding formation in a wellbore zone located above the set zonalisolation device; removing the setting tool assembly and the one or moreperforating guns coupled to the setting tool assembly from the wellbore;pumping fluid (e.g., a fracturing fluid such as a slickwater, a gelfluid, a proppant-laden fluid) from the surface down the wellbore andinto the formation via the plurality of perforations in the wellborezone above the set zonal isolation device and fracturing the formation,wherein a sealing device such as a ball is not required to be pumpedfrom the surface in order to prevent fluid flow through the set zonalisolation device and divert the fluid into the perforations andsurrounding formation; and rupturing the rupture disk to provide forfluid flow through the set zonal isolation device, wherein the fluidflow through the set zonal isolation device enhances the dissolutionrate of one or more dissolvable components of the zonal isolationdevice.

Referring to FIG. 24, disclosed herein is a method (e.g., a method ofhydraulic fracturing) comprising: inserting into a cased wellbore thezonal isolation device; actuating the zonal isolation device to providea set zonal isolation device, wherein the flapper transitions to thefully closed position and a wellbore zone below the set zonal isolationdevice is isolated from fluid flow from a wellbore zone above the setzonal isolation device; detaching a setting tool assembly from the setzonal isolation device; moving the setting tool assembly uphole from theset zonal isolation device, wherein the setting tool assembly is coupledto one or more perforating guns located uphole from the setting toolassembly; sending a trigger signal to the one or more perforating guns;forming a plurality of perforations through the casing and into thesurrounding formation in a wellbore zone located above the set zonalisolation device; removing the setting tool assembly and the one or moreperforating guns coupled to the setting tool assembly from the wellbore;pumping fluid (e.g., a fracturing fluid such as a slickwater, a gelfluid, a proppant-laden fluid) from the surface down the wellbore andinto the formation via the plurality of perforations in the wellborezone above the set zonal isolation device and fracturing the formation,wherein a sealing device such as a ball is not required to be pumpedfrom the surface in order to prevent fluid flow through the set zonalisolation device and divert the fluid into the perforations andsurrounding formation; and decoupling an end of the flapper proximatethe releasable hinge to remove the flapper from contact with the sealingsurface to provide for fluid flow through set zonal isolation device,wherein the fluid flow through the set isolation device enhances thedissolution rate of one or more dissolvable components of the zonalisolation device.

One advantage of the disclosure is to be able to avoid the act ofpumping a ball onto the frac plug for sealing purpose to divert thefracturing fluid into the perforations and surrounding formation. Thepumping of the ball increases the water usage and increases theoperating time for each stage of fracturing. Also a traditional springloaded ball does not work with a bottom-set plug because the ball blocksthe usage of the setting tool. By avoiding the usage of the ball, thedisclosure saves water and operating time for each stage of fracturing,and can be used with a bottom-set plug. Another advantage is that thedisclosure simplifies the design, reduces the leak paths, and reducesthe cost of the frac plug, by attaching a rotatable flow restrictor (arotatable sealing component 400) at an axially fixed distance withrespect to the frustum of the frac plug that supports the sealingsurface. There are no other frac plugs, especially dissolvable fracplugs, that have a rotatable flow restrictor at an axially fixeddistance with respect to the frustum of the frac plug that supports thesealing surface. This disclosure can be applied to a dissolvable fracplug, such as the Sprire™ frac plug, which is commercially availablefrom Halliburton Energy Services, Inc. Another advantage is that thereis no mandrel in the frac plug in this disclosure after the plug is set.The feature of no mandrel simplifies the design, thus reduces the amountof material used which aids in dissolution or milling, and lowers thecost of the plug. Another advantage is that the mule shoe (the endelement 170) of this design falls away after the setting process. Thelack of a mandrel and the removal of the mule shoe provides forincreased surface area for contact with a wellbore fluid, which allowsfor a more controlled (e.g., faster) dissolution process.

ADDITIONAL DISCLOSURE

The following enumerated aspects of the present disclosure are providedas non-limiting examples.

A first embodiment, which is a zonal isolation device 200 comprising asealing element 100 comprising a deformable material and an inner bore105, a support ring 190 (also referred to as an expansion ring, forexample a frustum having a conical shape) movably disposed within theinner bore 105 of the sealing element 100, a rotatable seal connected tothe support ring 190 and configured to engage a sealing surface (e.g.,face or seat) of support ring 190, wherein the flapper is configured torestrict fluid flow through the zonal isolation device 200 in a closedposition, is configured to minimally restrict fluid flow through thezonal isolation device 200 in a fully open position.

A second embodiment, which is a zonal isolation device comprising amandrel having a bore extending axially there through, an anchoringassembly (e.g., slip) circumferentially disposed about the mandrel andconfigured to expand and engage with a downhole surface, a sealingelement circumferentially disposed about the mandrel and configured tocompress and create a seal with the downhole surface, and a flappercoupled to the mandrel and configured to engage a sealing surface (e.g.,face or seat) of an end of the mandrel and seal the bore of the mandrel,wherein the flapper blocks fluid flow through the zonal isolation devicein a fully closed position, allows unrestricted fluid flow through thezonal isolation device in a fully open position, and allows restrictedfluid flow through the zonal isolation device when held by a proppingcomponent (also referred to as a propping member) in an intermediate orpartially open position.

A third embodiment, which is the device of the first or the secondembodiment, wherein the propping component comprises a spring (427and/or 445).

A fourth embodiment, which is the device of the third embodiment,wherein the spring is a torsion spring 427 (e.g., a flat spiral springor a clock spring), wherein the torsion spring is positioned adjacent ahinged end of the flapper and wherein the torsion spring holds theflapper in the intermediate position when the torsion spring is in aneutral or equilibrium (e.g., non-compressed and non-stretched)state/condition, thereby allowing fluid flow via a gap formed betweenflapper end 432 and the sealing surface as indicated by flow arrow 446.

A fifth embodiment, which is the device of the third embodiment, whereinthe spring is a coil spring 445, wherein a first end of the coil springis received within a recess 441 in the uphole end of the support ring190 and a second end of the coil spring 445 contacts flapper end 432,wherein the coil spring holds the flapper in the intermediate positionwhen the coil spring is in a neutral or equilibrium (e.g.,non-compressed and non-stretched) state/condition, thereby allowingfluid flow via a gap formed between flapper end 432 and the sealingsurface as indicated by flow arrow 446.

A sixth embodiment, which is the device of the first or the thirdembodiment, wherein the propping component comprises a strut 448.

A seventh embodiment, which is the device of the sixth embodiment,wherein a first end of the strut 448 is received within a recess 441 inthe uphole end of the support ring 190 and a second end of the strut 448contacts flapper end 432, wherein the strut holds the flapper in theintermediate position, thereby allowing fluid flow via a gap formedbetween flapper end 432 and the sealing surface as indicated by flowarrow 446.

An eighth embodiment, which is the device of the seventh embodiment,wherein the strut comprises a dissolvable material, a degradablematerial, an erodible material, an abradable material, atemperature-sensitive material (e.g., a fusible alloy), a corrodiblematerial, a frangible material, or combinations thereof and isconfigured such that the strut loses structural integrity when subjectedto contact with a wellbore fluid (e.g., downhole fluid flow), downholeambient conditions (e.g., temperature and/or pressure), or both, therebyallowing the flapper to transition from the intermediate position to thefully closed position.

A ninth embodiment, which is the device of any of the first through theeighth embodiments, wherein the flapper further comprises a rupture disk435 (also referred to as a burst disk or burst diaphragm), whichoptionally may be protected by one or more coating layers 437. Thecoating layers 437 are for protection only and do not preventapplication of pressure on the rupture disk or otherwise hinderoperation of the rupture disk.

A tenth embodiment, which is the device of the ninth embodiment, whereinthe rupture disk is disposed within a circumferential groove on aninterior face of a hole or bore passing through the flapper.

An eleventh embodiment, which is the device of any of the first throughthe tenth embodiments, wherein the flapper further comprises areleasable hinge configured to decouple an end of the flapper proximatethe releasable hinge.

A twelfth embodiment, which is the device of the eleventh embodiment,wherein the releasable hinge comprises a pivot pin and wherein the endof the flapper proximate the releasable hinge comprises a u-shapedrecess 438 receiving the pivot pin and a clip 442 (e.g., a pinch clip)engaging the pivot pin, wherein the flapper is configured to decouplefrom the releasable hinge via application of a releasing forcesufficient to overcome a retaining force applied to the releasable hingeby the clip 442, for example a releasing force applied via flow ofwellbore fluid as represented by flow arrows 440.

A thirteenth embodiment, which is a zonal isolation device 200comprising a sealing element 100 comprising a deformable material and aninner bore 105, a support ring 190 (also referred to as a frustum havinga conical shape) movably disposed within the inner bore 105 of thesealing element 100, a flapper connected to an uphole end of the supportring 190 and configured to engage a sealing surface (e.g., face or seat)of support ring 190, wherein the flapper blocks fluid flow through thezonal isolation device 200 in a fully closed position and allowsunrestricted fluid flow through the zonal isolation device 200 in afully open position and wherein the flapper further comprises a rupturedisk 435 (also referred to as a burst disk or burst diaphragm), whichoptionally may be protected by one or more coating layers 437, a wedge180 engaged with a downhole end of the sealing element 100, an anchoringassembly 215 engaged with the wedge 180, and an end element 170 (e.g., amule shoe) adjacent the anchoring assembly 215.

A fourteenth embodiment, which is a zonal isolation device comprising amandrel having a bore extending axially there through, an anchoringassembly (e.g., slip) circumferentially disposed about the mandrel andconfigured to expand and engage with a downhole surface, a sealingelement circumferentially disposed about the mandrel and configured tocompress and create a seal with the downhole surface, and a flappercoupled to the mandrel and configured to engage a sealing surface (e.g.,face or seat) of an end of the mandrel and seal the bore of the mandrel,wherein the flapper blocks fluid flow through the zonal isolation devicein a fully closed position and allows unrestricted fluid flow throughthe zonal isolation device in a fully open position and wherein theflapper further comprises a rupture disk 435 (also referred to as aburst disk or burst diaphragm), which optionally may be protected by oneor more coating layers 437.

A fifteenth embodiment, which is the device of the thirteenth or thefourteenth embodiment, wherein the rupture disk is disposed within acircumferential groove on an interior face of a hole passing through theflapper.

A sixteenth embodiment, which is a zonal isolation device 200 comprisinga sealing element 100 comprising a deformable material and an inner bore105, a support ring 190 (also referred to as a frustum having a conicalshape) movably disposed within the inner bore 105 of the sealing element100, a flapper connected to an uphole end of the support ring 190 andconfigured to engage a sealing surface (e.g., face or seat) of supportring 190, wherein the flapper blocks fluid flow through the zonalisolation device 200 in a fully closed position and allows unrestrictedfluid flow through the zonal isolation device 200 in a fully openposition and wherein the flapper further comprises a releasable hingeconfigured to decouple an end of the flapper proximate the releasablehinge, a wedge 180 engaged with a downhole end of the sealing element100, an anchoring assembly 215 engaged with the wedge 180, and an endelement 170 (e.g., a mule shoe) adjacent the anchoring assembly 215.

A seventeenth embodiment, which is a zonal isolation device comprising amandrel having a bore extending axially there through, an anchoringassembly (e.g., slip) circumferentially disposed about the mandrel andconfigured to expand and engage with a downhole surface, a sealingelement circumferentially disposed about the mandrel and configured tocompress and create a seal with the downhole surface, and a flappercoupled to the mandrel and configured to engage a sealing surface (e.g.,face or seat) of an end of the mandrel and seal the bore of the mandrel,wherein the flapper blocks fluid flow through the zonal isolation devicein a fully closed position and allows unrestricted fluid flow throughthe zonal isolation device in a fully open position and wherein theflapper further comprises a releasable hinge configured to decouple anend of the flapper proximate the releasable hinge.

An eighteenth embodiment, which is the device of the sixteenth or theseventeenth embodiment, wherein the releasable hinge comprises a pivotpin and wherein the end of the flapper proximate the releasable hingecomprises a u-shaped recess 438 receiving the pivot pin and a clip 442(e.g., a pinch clip) engaging the pivot pin, wherein the flapper isconfigured to decouple from the releasable hinge via application of areleasing force sufficient to overcome a retaining force applied to thereleasable hinge by the clip 442, for example a releasing force appliedvia flow of wellbore fluid as represented by flow arrows 440.

A nineteenth embodiment, which is a method comprising inserting into acased wellbore the zonal isolation device of any of the first throughthe twelfth embodiments, actuating the zonal isolation device to providea set zonal isolation device, detaching a setting tool assembly from theset zonal isolation device, moving the setting tool assembly uphole fromthe set zonal isolation device, wherein the setting tool assembly iscoupled to one or more perforating guns located uphole from the settingtool assembly, sending a trigger signal to the one or more perforatingguns, and upon failure of at least one of the perforating guns to fire,pumping one or more replacement perforating guns down the wellbore to adesired location, wherein during the pumping the propping componentholds the rotatable sealing component (e.g., flapper) in theintermediate position and provides for restricted flow of a wellborefluid through the zonal isolation device.

A twentieth embodiment, which is the method of the nineteenthembodiment, further comprising sending a trigger signal to the one ormore replacement perforating guns, and forming a plurality ofperforations through the casing and into the surrounding formation in awellbore zone located above the set zonal isolation device.

A twenty-first embodiment, which is the method of the twentiethembodiment, further comprising removing the setting tool assembly, theone or more perforating guns coupled to the setting tool assembly, andthe one or more replacement perforating guns from the wellbore.

A twenty-second embodiment, which is the method of the twenty-firstembodiment, further comprising structurally compromising the proppingcomponent such that the rotatable sealing component (e.g., flapper) cantransition to the fully closed position, whereby a wellbore zone belowthe set zonal isolation device is isolated from fluid flow from thewellbore zone above the set zonal isolation device.

A twenty-third embodiment, which is the method of the twenty-secondembodiment, wherein the propping component comprises a degradablematerial, an erodible material, or an abradable material and isstructurally compromised via contact with a flowing wellbore fluid thatremoves all or a portion of the degradable material, the erodiblematerial, or the abradable material.

A twenty-fourth embodiment, which is the method of the twenty-secondembodiment, wherein the propping component comprises a dissolvablematerial or a corrodible material and is structurally compromised viacontact with a wellbore fluid (e.g., via chemical decomposition of thestrut, dissolution of the strut, etc.).

A twenty-fifth embodiment, which is the method of the twenty-secondembodiment, wherein the propping component comprises atemperature-sensitive material (e.g., a fusible alloy) and isstructurally compromised via change in ambient temperature in thewellbore proximate the set zonal isolation plug.

A twenty-sixth embodiment, which is the method of the twenty-fifthembodiment, wherein the change in ambient temperature is controlled byadjusting (e.g., halting) a flow of fluid in the wellbore, therebyallowing the temperature in the wellbore proximate the set zonalisolation plug to increase and soften the temperature-sensitivematerial.

A twenty-seventh embodiment, which is the method of the twenty-secondembodiment, wherein the propping component comprises a frangiblematerial and is structurally compromised via contact with a pressurewave.

A twenty-eighth embodiment, which is the method of the twenty-seventhembodiment, wherein the pressure wave is produced via a fluid pulse fromthe surface or from firing of a perforating gun (e.g., a shock wave).

A twenty-ninth embodiment, which is the method of the twenty-firstembodiment, further comprising applying a closing force on the rotatablesealing component (e.g., flapper) that is greater than a spring forceapplied by spring 427 and/or spring 445 to transition the rotatablesealing component (e.g., flapper) from the intermediate position to thefully closed position, wherein the closing force results from contactwith fluid flowing into the wellbore.

A thirtieth embodiment, which is the method of any of the twenty-secondthrough the twenty-ninth embodiments, further comprising pumping fluid(e.g., a fracturing fluid such as a slickwater, a gel fluid, aproppant-laden fluid) from the surface down the wellbore and into theformation via the plurality of perforations in the wellbore zone abovethe set zonal isolation device and fracturing the formation, wherein asealing device such as a ball is not required to be pumped from thesurface in order to prevent fluid flow through the zonal isolationdevice and divert the fluid into the perforations and surroundingformation.

A thirty-first embodiment, which is the method of the thirtiethembodiment, where the rotatable sealing component (e.g., flapper)comprises a rupture disk, rupturing the rupture disk to provide forfluid flow through the set zonal isolation device, wherein the fluidflow enhances the dissolution rate of one or more dissolvable componentsof the zonal isolation device.

A thirty-second embodiment, which is the method of the thirtiethembodiment, where the rotatable sealing component (e.g., flapper)comprises a releasable hinge, decoupling an end of the rotatable sealingcomponent (e.g., flapper) proximate the releasable hinge to remove therotatable sealing component (e.g., flapper) from contact with thesealing surface to provide for fluid flow through the set zonalisolation device, wherein the fluid flow enhances the dissolution rateof one or more dissolvable components of the zonal isolation device.

A thirty-third embodiment, which is a method comprising inserting into acased wellbore the zonal isolation device of any of the first throughthe twelfth embodiments, actuating the zonal isolation device to providea set zonal isolation device, detaching a setting tool assembly from theset zonal isolation device, moving the setting tool assembly uphole fromthe set zonal isolation device, wherein the setting tool assembly iscoupled to one or more perforating guns located uphole from the settingtool assembly, sending a trigger signal to the one or more perforatingguns, forming a plurality of perforations through the casing and intothe surrounding formation in a wellbore zone located above the set zonalisolation device, removing the setting tool assembly and the one or moreperforating guns coupled to the setting tool assembly from the wellbore,either (i) structurally compromising the propping component such thatthe rotatable sealing component (e.g., flapper) can transition to thefully closed position, whereby a wellbore zone below the set zonalisolation device is isolated from fluid flow from the wellbore zoneabove the set zonal isolation device, wherein the propping component isstructurally compromised in accordance with any of the twenty-thirdthrough the twenty-eighth embodiments or (ii) applying a closing forceon the rotatable sealing component (e.g., flapper) that is greater thana spring force applied by spring 427 and/or spring 445 to transition therotatable sealing component (e.g., flapper) from the intermediateposition to the fully closed position, wherein the closing force resultsfrom contact with fluid flowing into the wellbore, and pumping fluid(e.g., a fracturing fluid such as a slickwater, a gel fluid, aproppant-laden fluid) from the surface down the wellbore and into theformation via the plurality of perforations in the wellbore zone abovethe set zonal isolation device and fracturing the formation, wherein asealing device such as a ball is not required to be pumped from thesurface in order to prevent fluid flow through the zonal isolationdevice and divert the fluid into the perforations and surroundingformation.

A thirty-fourth embodiment, which is the method of the thirty-secondembodiment, where the rotatable sealing component (e.g., flapper)comprises a rupture disk, rupturing the rupture disk to provide forfluid flow through the set zonal isolation device, wherein the fluidflow enhances the dissolution rate of one or more dissolvable componentsof the zonal isolation device.

A thirty-fifth embodiment, which is the method of the thirty-secondembodiment, where the rotatable sealing component (e.g., flapper)comprises a releasable hinge, decoupling an end of the rotatable sealingcomponent (e.g., flapper) proximate the releasable hinge to remove therotatable sealing component (e.g., flapper) from contact with thesealing surface to provide for fluid flow through the set zonalisolation device, wherein the fluid flow enhances the dissolution rateof one or more dissolvable components of the zonal isolation device.

A thirty-sixth embodiment, which is a method comprising inserting into acased wellbore the zonal isolation device of any of the thirteenththrough the fifteenth embodiments, actuating the zonal isolation deviceto provide a set zonal isolation device, wherein the rotatable sealingcomponent (e.g., flapper) transitions to the fully closed position and awellbore zone below the set zonal isolation device is isolated fromfluid flow from a wellbore zone above the set zonal isolation device,detaching a setting tool assembly from the set zonal isolation device,moving the setting tool assembly uphole from the set zonal isolationdevice, wherein the setting tool assembly is coupled to one or moreperforating guns located uphole from the setting tool assembly, sendinga trigger signal to the one or more perforating guns, forming aplurality of perforations through the casing and into the surroundingformation in a wellbore zone located above the set zonal isolationdevice, removing the setting tool assembly and the one or moreperforating guns coupled to the setting tool assembly from the wellbore,pumping fluid (e.g., a fracturing fluid such as a slickwater, a gelfluid, a proppant-laden fluid) from the surface down the wellbore andinto the formation via the plurality of perforations in the wellborezone above the set zonal isolation device and fracturing the formation,wherein a sealing device such as a ball is not required to be pumpedfrom the surface in order to prevent fluid flow through the set zonalisolation device and divert the fluid into the perforations andsurrounding formation, and rupturing the rupture disk to provide forfluid flow through the set zonal isolation device, wherein the fluidflow enhances the dissolution rate of one or more dissolvable componentsof the zonal isolation device.

A thirty-seventh embodiment, which is a method comprising inserting intoa cased wellbore the zonal isolation device of any of the sixteenththrough the eighteenth embodiments, actuating the zonal isolation deviceto provide a set zonal isolation device, wherein the rotatable sealingcomponent (e.g., flapper) transitions to the fully closed position and awellbore zone below the set zonal isolation device is isolated fromfluid flow from a wellbore zone above the set zonal isolation device,detaching a setting tool assembly from the set zonal isolation device,moving the setting tool assembly uphole from the set zonal isolationdevice, wherein the setting tool assembly is coupled to one or moreperforating guns located uphole from the setting tool assembly, sendinga trigger signal to the one or more perforating guns, forming aplurality of perforations through the casing and into the surroundingformation in a wellbore zone located above the set zonal isolationdevice, removing the setting tool assembly and the one or moreperforating guns coupled to the setting tool assembly from the wellbore,pumping fluid (e.g., a fracturing fluid such as a slickwater, a gelfluid, a proppant-laden fluid) from the surface down the wellbore andinto the formation via the plurality of perforations in the wellborezone above the set zonal isolation device and fracturing the formation,wherein a sealing device such as a ball is not required to be pumpedfrom the surface in order to prevent fluid flow through the set zonalisolation device and divert the fluid into the perforations andsurrounding formation, and decoupling an end of the rotatable sealingcomponent (e.g., flapper) proximate the releasable hinge to remove therotatable sealing component (e.g., flapper) from contact with thesealing surface to provide for fluid flow through set zonal isolationdevice, wherein the fluid flow enhances the dissolution rate of one ormore dissolvable components of the zonal isolation device.

A thirty-eighth embodiment, which is a zonal isolation device 200comprising: a sealing element 100 comprising a deformable material andan inner bore 105; a support ring 190 (also referred to as a frustumhaving a conical shape) movably disposed within the inner bore 105 ofthe sealing element 100; a rotatable seal connected to the support ring190 and configured to engage a sealing surface (e.g., face or seat) ofsupport ring 190, wherein the flapper is configured to restrict fluidflow through the zonal isolation device 200 in a closed position, isconfigured to minimally restrict fluid flow through the zonal isolationdevice 200 in a fully open position an end element 170 (e.g., a muleshoe) adjacent the anchoring assembly 215.

A thirty-ninth embodiment, which is the zonal isolation device of thethirty-eighth embodiment wherein the rotatable member allows restrictedfluid flow through the zonal isolation device 200 when held by apropping component (also referred to as a propping member) in anintermediate or partially open position.

A fortieth embodiment, which is a zonal isolation device 200 comprising:a sealing element 100 comprising a deformable material and an inner bore105; a support ring movably disposed within the inner bore 105 of thesealing element 100; a rotatable sealing component 400 coupled to thesupport ring 190 and configured to engage a sealing surface of thesupport ring 190, wherein the rotatable sealing component blocks fluidflow through the zonal isolation device 200 in a fully closed position,allows unrestricted fluid flow through the zonal isolation device 200 ina fully open position, and allows restricted fluid flow through thezonal isolation device 200 when held by a propping component in anintermediate or partially open position.

A forty-first embodiment, which is the device of the fortiethembodiment, wherein the rotatable sealing component 400 is a flappervalve.

Therefore, the present disclosure is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, as thepresent disclosure may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. While numerous changes may be made bythose skilled in the art, such changes are encompassed within the spiritof the subject matter defined by the appended claims. Furthermore, nolimitations are intended to the details of construction or design hereinshown, other than as described in the claims below. It is thereforeevident that the particular illustrative embodiments disclosed above maybe altered or modified and all such variations are considered within thescope and spirit of the present disclosure. In particular, every rangeof values (e.g., “from about a to about b,” or, equivalently, “fromapproximately a to b,” or, equivalently, “from approximately a-b”)disclosed herein is to be understood as referring to the power set (theset of all subsets) of the respective range of values. The terms in theclaims have their plain, ordinary meaning unless otherwise explicitlyand clearly defined by the patentee.

What is claimed is:
 1. A zonal isolation device comprising: a sealingelement comprising a deformable material and an inner bore; a supportring movably disposed within the inner bore of the sealing element; aflapper coupled to the support ring and configured to engage a sealingsurface of support ring, wherein the flapper blocks fluid flow throughthe zonal isolation device in a fully closed position and allowsunrestricted fluid flow through the zonal isolation device in a fullyopen position and wherein the flapper further comprises a rupture disk;a wedge engaged with a downhole end of the sealing element; an anchoringassembly engaged with the wedge; and an end element adjacent theanchoring assembly.
 2. The device of claim 1, wherein the rupture diskis disposed within a circumferential groove on an interior face of ahole passing through the flapper.
 3. The device of claim 1, wherein therupture disk comprises one or more coating layers.
 4. The device ofclaim 1, wherein the flapper further comprises a releasable hingeconfigured to decouple an end of the flapper proximate the releasablehinge.
 5. The device of claim 2, wherein the flapper further comprises areleasable hinge configured to decouple an end of the flapper proximatethe releasable hinge.
 6. The device of claim 5, wherein the end of theflapper proximate the releasable hinge comprises a u-shaped recessreceiving the pivot pin and a clip engaging the pivot pin.
 7. The deviceof claim 6, wherein the flapper is configured to decouple from thereleasable hinge via application of a releasing force sufficient toovercome a retaining force applied to the releasable hinge by the clip.8. A method comprising: inserting into a cased wellbore the zonalisolation device of claim 1; actuating the zonal isolation device toprovide a set zonal isolation device, wherein the flapper transitions tothe fully closed position and a wellbore zone below the set zonalisolation device is isolated from fluid flow from a wellbore zone abovethe set zonal isolation device; detaching a setting tool assembly fromthe set zonal isolation device; moving the setting tool assembly upholefrom the set zonal isolation device, wherein the setting tool assemblyis coupled to one or more perforating guns located uphole from thesetting tool assembly; sending a trigger signal to the one or moreperforating guns; forming a plurality of perforations through the casingand into the surrounding formation in a wellbore zone located above theset zonal isolation device; removing the setting tool assembly and theone or more perforating guns coupled to the setting tool assembly fromthe wellbore; pumping fluid from the surface down the wellbore and intothe formation via the plurality of perforations in the wellbore zoneabove the set zonal isolation device and fracturing the formation; andrupturing the rupture disk to provide for fluid flow through the setzonal isolation device.
 9. The method of claim 8, wherein the fluid flowthrough the set zonal isolation device enhances the dissolution rate ofone or more dissolvable components of the zonal isolation device. 10.The method of claim 9, wherein a sealing device such as a ball is notrequired to be pumped from the surface in order to prevent fluid flowthrough the set zonal isolation device and divert the fluid into theperforations and surrounding formation.
 11. The method of claim 10,wherein the fluid is slickwater, a gelled fluid, or a proppant-ladenfluid.
 12. The method of claim 8, wherein the flapper further comprisesa releasable hinge configured to decouple an end of the flapperproximate the releasable hinge and further comprising decoupling an endof the flapper proximate the releasable hinge to remove the flapper fromcontact with the sealing surface to provide for fluid flow through setzonal isolation device.
 13. A zonal isolation device comprising: asealing element comprising a deformable material and an inner bore; asupport ring movably disposed within the inner bore of the sealingelement; a flapper coupled to the support ring and configured to engagea sealing surface of support ring, wherein the flapper blocks fluid flowthrough the zonal isolation device in a fully closed position and allowsunrestricted fluid flow through the zonal isolation device in a fullyopen position and wherein the flapper further comprises a releasablehinge configured to decouple an end of the flapper proximate thereleasable hinge; a wedge engaged with a downhole end of the sealingelement; an anchoring assembly engaged with the wedge; and an endelement adjacent the anchoring assembly.
 14. The device of claim 13,wherein the releasable hinge comprises a pivot pin.
 15. The device ofclaim 14, wherein the end of the flapper proximate the releasable hingecomprises a u-shaped recess receiving the pivot pin and a clip engagingthe pivot pin.
 16. The device of claim 15, wherein the flapper isconfigured to decouple from the releasable hinge via application of areleasing force sufficient to overcome a retaining force applied to thereleasable hinge by the clip.
 17. A method comprising: inserting into acased wellbore the zonal isolation device; actuating the zonal isolationdevice to provide a set zonal isolation device, wherein the flappertransitions to the fully closed position and a wellbore zone below theset zonal isolation device is isolated from fluid flow from a wellborezone above the set zonal isolation device; detaching a setting toolassembly from the set zonal isolation device; moving the setting toolassembly uphole from the set zonal isolation device, wherein the settingtool assembly is coupled to one or more perforating guns located upholefrom the setting tool assembly; sending a trigger signal to the one ormore perforating guns; forming a plurality of perforations through thecasing and into the surrounding formation in a wellbore zone locatedabove the set zonal isolation device; removing the setting tool assemblyand the one or more perforating guns coupled to the setting toolassembly from the wellbore; pumping fluid from the surface down thewellbore and into the formation via the plurality of perforations in thewellbore zone above the set zonal isolation device and fracturing theformation; and decoupling an end of the flapper proximate the releasablehinge to remove the flapper from contact with the sealing surface toprovide for fluid flow through set zonal isolation device.
 18. Themethod of claim 17, wherein the fluid flow through the set isolationdevice enhances the dissolution rate of one or more dissolvablecomponents of the zonal isolation device.
 19. The method of claim 18,wherein a sealing device such as a ball is not required to be pumpedfrom the surface in order to prevent fluid flow through the set zonalisolation device and divert the fluid into the perforations andsurrounding formation.
 20. The method of claim 19, wherein the fluid isslickwater, a gelled fluid, or a proppant-laden fluid.